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Sample records for certification ensemble une

  1. Les interpr\\'etations de la m\\'ecanique quantique : une vue d'ensemble introductive

    CERN Document Server

    Boyer-Kassem, Thomas

    2015-01-01

    La m\\'ecanique quantique est une th\\'eorie physique contemporaine r\\'eput\\'ee pour ses d\\'efis au sens commun et ses paradoxes. Depuis bient\\^ot un si\\`ecle, plusieurs interpr\\'etations de la th\\'eorie ont \\'et\\'e propos\\'ees par les physiciens et les philosophes, offrant des images quantiques du monde, ou des m\\'etaphysiques, radicalement diff\\'erentes. L'existence d'un hasard fondamental, ou d'une multitude de mondes en-dehors du n\\^otre, d\\'epend ainsi de l'interpr\\'etation adopt\\'ee. Cet article, en s'appuyant sur le livre Boyer-Kassem (2015), Qu'est-ce que la m\\'ecanique quantique ?, pr\\'esente trois principales interpr\\'etations quantiques, empiriquement \\'equivalentes : l'interpr\\'etation dite orthodoxe, l'interpr\\'etation de Bohm, et l'interpr\\'etation des mondes multiples. Quantum mechanics is a contemporary physical theory which is famous for its paradoxes. For about a century, several interpretations of the theory have been proposed by physicists and philosophers, giving very different images of th...

  2. Les interprétations de la mécanique quantique: : une vue d'ensemble introductive

    NARCIS (Netherlands)

    Boyer, Thomas

    2015-01-01

    La mécanique quantique est une théorie physique contemporaine réputée pour ses défis au sens commun et ses paradoxes. Depuis bientôt un siècle, plusieurs interprétations de la théorie ont été proposées par les physiciens et les philosophes, offrant des images quantiques du monde, ou des métaphysique

  3. Jeter les bases d'une conception d'ensemble des liens entre activité-compétence-professionnalisation/ développement professionnel-identité

    OpenAIRE

    Wittorski, Richard

    2009-01-01

    Tant dans les milieux du travail que ceux de la formation, plusieurs vocables tels compétence, professionnalisation, identité,... font l'objet d'une forte valorisation sociale qui explique en grande partie d'ailleurs la variété des définitions proposées (quand elles sont explicites) en lien avec des usages sociaux et scientifiques variés. Au fond, c'est bien souvent l'usage qui suggère voire détermine le sens attribué à ces " concepts sociaux ". Nous souhaitons ici adopter la posture du cherc...

  4. Une formation à distance pour la certification des compétences à l’ère du numérique : le projet C2i Université Laval - Université de Bordeaux

    Directory of Open Access Journals (Sweden)

    Jean-François Lévesque

    2010-01-01

    Full Text Available [Français] Il est désormais devenu indispensable de maîtriser les technologies de l’information et de la communication (TIC pour entreprendre avec succès des études universitaires. Sur ce point, la prise de conscience est de plus en plus forte et la question de la certification des compétences requises à l’ère du numérique devient un enjeu pour les universités. À partir d’un projet pilote mené dans le cadre de la collaboration internationale entre l’Université Laval (Québec et l’Université de Bordeaux (France, nous nous interrogeons dans cet article sur les conditions de mise en place d’une formation à distance en réponse à cette préoccupation. [English] It is now essential to master information and communication technologies (ICT skills to successfully undertake university studies. As there is a growing awareness in this regard, the certification of the skills required in the digital age becomes an issue for universities. Following a pilot project conducted by Laval University (Quebec and by Bordeaux University (France, we examine in this paper the conditions for setting up a distance learning course in response to this concern.

  5. Ensemble Methods

    Science.gov (United States)

    Re, Matteo; Valentini, Giorgio

    2012-03-01

    Ensemble methods are statistical and computational learning procedures reminiscent of the human social learning behavior of seeking several opinions before making any crucial decision. The idea of combining the opinions of different "experts" to obtain an overall “ensemble” decision is rooted in our culture at least from the classical age of ancient Greece, and it has been formalized during the Enlightenment with the Condorcet Jury Theorem[45]), which proved that the judgment of a committee is superior to those of individuals, provided the individuals have reasonable competence. Ensembles are sets of learning machines that combine in some way their decisions, or their learning algorithms, or different views of data, or other specific characteristics to obtain more reliable and more accurate predictions in supervised and unsupervised learning problems [48,116]. A simple example is represented by the majority vote ensemble, by which the decisions of different learning machines are combined, and the class that receives the majority of “votes” (i.e., the class predicted by the majority of the learning machines) is the class predicted by the overall ensemble [158]. In the literature, a plethora of terms other than ensembles has been used, such as fusion, combination, aggregation, and committee, to indicate sets of learning machines that work together to solve a machine learning problem [19,40,56,66,99,108,123], but in this chapter we maintain the term ensemble in its widest meaning, in order to include the whole range of combination methods. Nowadays, ensemble methods represent one of the main current research lines in machine learning [48,116], and the interest of the research community on ensemble methods is witnessed by conferences and workshops specifically devoted to ensembles, first of all the multiple classifier systems (MCS) conference organized by Roli, Kittler, Windeatt, and other researchers of this area [14,62,85,149,173]. Several theories have been

  6. NYYD Ensemble

    Index Scriptorium Estoniae

    2002-01-01

    NYYD Ensemble'i duost Traksmann - Lukk E.-S. Tüüri teosega "Symbiosis", mis on salvestatud ka hiljuti ilmunud NYYD Ensemble'i CDle. 2. märtsil Rakvere Teatri väikeses saalis ja 3. märtsil Rotermanni Soolalaos, kavas Tüür, Kaumann, Berio, Reich, Yun, Hauta-aho, Buckinx

  7. L’ensemble du Main Building au CERN à Genève, Peter Steiger et Rudolf Steiger architectes, Carl Hubacher, Fietz et Hauri ingénieurs, 1954-1960 recommandations pour une réhabilitation

    CERN Document Server

    Wohlschlag, Jérôme; Marino, Giulia

    Les bâtiments qui ont écrit l’histoire de l’architecture moderne vivent une période décisive: souffrant de nombreux maux dus à leurs âges, d’une méconnaissance, et parfois même d’une certaine impopularité, les menaces sont de plus en plus concrètes: d’une transformation normative et inadaptée jusqu’à la démolition. Ces oeuvres représentent un réel patrimoine pour la collectivité, que les effets du temps ont fini par occulter. Le vieillissement et le pragmatisme quotidien transformant l’édifice, les qualités qui l’ont placé au statut qu’on lui a reconnu ne sont presque plus perceptibles. Pourtant, ces édifices recèlent un grand potentiel; pour les maîtres d’ouvrage au bénéfice d’un bien valorisé, exploité et emblématique d’une part; pour la société enrichissant son patrimoine culturel d’autre part; finalement pour les architectes comme moyen de connaissance, source d’inspiration et ressource professionnelle. Le site du CERN à Meyrin, de par son extrater...

  8. La rispéridone en pédopsychiatrie. Sa place dans l’ensemble de la nosologie, dont les diagnostics non-psychotiques, les liens avec la clinique, des modèles neurophysiologiques d’actions, dont une amélioration de la synthèse des perceptions des émotions ,contexte sociologique et aspects éthiques et anthropologiques.

    OpenAIRE

    Scholl, Jean-Marc

    2004-01-01

    Certains enfants bénéficient largement des antipsychotiques atypiques et, pour certains, le pronostic relationnel et développemental s’améliore nettement. Les indications concernent notamment des diagnostics non-psychotiques tels que : troubles de la personnalité borderline, anxiété de séparation, état maniaque, action de stabilisateur de l’humeur. Cet article est le fruit d’une expérience clinique se rapportant à plus de 230 patients. Il parcourt l’ensemble de la nosologie pédopsychiat...

  9. Une autre école en Espagne

    OpenAIRE

    Bolívar, Antonio

    2011-01-01

    Au cours des deux dernières décennies, le système éducatif espagnol a connu une succession de lois sur l’éducation qui étaient intimement liées aux différents gouvernements au pouvoir et répondaient aux nouvelles attentes de la société. Face à ce train de réformes qui ne parvient pas à changer les pratiques pédagogiques, un ensemble de mouvements réformistes montre qu’une autre école est possible. L’article analyse en premier lieu les principaux axes d’une approche communautaire de la réforme...

  10. Composed ensembles of random unitary ensembles

    CERN Document Server

    Pozniak, M; Kus, M; Pozniak, Marcin; Zyczkowski, Karol; Kus, Marek

    1997-01-01

    Composed ensembles of random unitary matrices are defined via products of matrices, each pertaining to a given canonical circular ensemble of Dyson. We investigate statistical properties of spectra of some composed ensembles and demonstrate their physical relevance. We discuss also the methods of generating random matrices distributed according to invariant Haar measure on the orthogonal and unitary group.

  11. Une épure de la Réunion

    Directory of Open Access Journals (Sweden)

    Jean-Louis GUÉBOURG

    1988-09-01

    Full Text Available L'espace de la Réunion se structure autour d'un centre vide et est marqué par une double dissymétrie entre les côtes au vent et sous le vent. Le site de sa principale agglomération ne se comprend que par un choix historique qui contraste avec la logique de l'organisation d'ensemble.

  12. Online Learning with Ensembles

    OpenAIRE

    Urbanczik, R

    1999-01-01

    Supervised online learning with an ensemble of students randomized by the choice of initial conditions is analyzed. For the case of the perceptron learning rule, asymptotically the same improvement in the generalization error of the ensemble compared to the performance of a single student is found as in Gibbs learning. For more optimized learning rules, however, using an ensemble yields no improvement. This is explained by showing that for any learning rule $f$ a transform $\\tilde{f}$ exists,...

  13. Une science du tourisme ?

    OpenAIRE

    Airey, David; Bédard, François; Ceriani-Sebregondi, Giorgia; Chapuis, Amandine; Dewailly, Jean-Michel; Drouin, Martin; Gay, Jean-Christophe; Hillali, Mimoun; Hoerner, Jean-Michel; Jolin, Louis; Kadri, Boualem; Rémy KNAFOU; Leman, Edward; Novakowski, Nick; Priskin, Julianna

    2009-01-01

    Avec ce numéro thématique, Téoros souhaite promouvoir un débat organisé dans une perspective internationale et pluridisciplinaire. L’objectif de ce numéro est de s’interroger à nouveau sur l’identité scientifique du tourisme, en tentant de mettre en évidence les handicaps épistémologiques et méthodologiques, de comprendre les raisons qui freinent la construction d’un consensus au sein de la communauté scientifique, d’identifier les conditions nécessaires à l’émergence d’une science du tourism...

  14. Chapitre VIII. À la recherche d’une méthode

    OpenAIRE

    Pisano, Giusy

    2013-01-01

    L’ensemble des recherches se concentre désormais autour d’une question fondamentale : quelle méthode adopter pour fixer le mouvement ? Plusieurs expériences donneront finalement naissance à des systèmes permettant de remplacer la sensation auditive et visuelle par une trace objective des phénomènes analysés. Parmi toutes ces recherches, une seulement sera durablement appliquée dans les expérimentations scientifiques : la méthode graphique. Néanmoins, le parcours qui mène à la reconnaissance d...

  15. Multilevel ensemble Kalman filtering

    OpenAIRE

    Hoel, Håkon; Law, Kody J. H.; Tempone, Raul

    2015-01-01

    This work embeds a multilevel Monte Carlo (MLMC) sampling strategy into the Monte Carlo step of the ensemble Kalman filter (ENKF), thereby yielding a multilevel ensemble Kalman filter (MLENKF) which has provably superior asymptotic cost to a given accuracy level. The theoretical results are illustrated numerically.

  16. Ensembl regulation resources.

    Science.gov (United States)

    Zerbino, Daniel R; Johnson, Nathan; Juetteman, Thomas; Sheppard, Dan; Wilder, Steven P; Lavidas, Ilias; Nuhn, Michael; Perry, Emily; Raffaillac-Desfosses, Quentin; Sobral, Daniel; Keefe, Damian; Gräf, Stefan; Ahmed, Ikhlak; Kinsella, Rhoda; Pritchard, Bethan; Brent, Simon; Amode, Ridwan; Parker, Anne; Trevanion, Steven; Birney, Ewan; Dunham, Ian; Flicek, Paul

    2016-01-01

    New experimental techniques in epigenomics allow researchers to assay a diversity of highly dynamic features such as histone marks, DNA modifications or chromatin structure. The study of their fluctuations should provide insights into gene expression regulation, cell differentiation and disease. The Ensembl project collects and maintains the Ensembl regulation data resources on epigenetic marks, transcription factor binding and DNA methylation for human and mouse, as well as microarray probe mappings and annotations for a variety of chordate genomes. From this data, we produce a functional annotation of the regulatory elements along the human and mouse genomes with plans to expand to other species as data becomes available. Starting from well-studied cell lines, we will progressively expand our library of measurements to a greater variety of samples. Ensembl's regulation resources provide a central and easy-to-query repository for reference epigenomes. As with all Ensembl data, it is freely available at http://www.ensembl.org, from the Perl and REST APIs and from the public Ensembl MySQL database server at ensembldb.ensembl.org. Database URL: http://www.ensembl.org. PMID:26888907

  17. A Classifier Ensemble of Binary Classifier Ensembles

    Directory of Open Access Journals (Sweden)

    Sajad Parvin

    2011-09-01

    Full Text Available This paper proposes an innovative combinational algorithm to improve the performance in multiclass classification domains. Because the more accurate classifier the better performance of classification, the researchers in computer communities have been tended to improve the accuracies of classifiers. Although a better performance for classifier is defined the more accurate classifier, but turning to the best classifier is not always the best option to obtain the best quality in classification. It means to reach the best classification there is another alternative to use many inaccurate or weak classifiers each of them is specialized for a sub-space in the problem space and using their consensus vote as the final classifier. So this paper proposes a heuristic classifier ensemble to improve the performance of classification learning. It is specially deal with multiclass problems which their aim is to learn the boundaries of each class from many other classes. Based on the concept of multiclass problems classifiers are divided into two different categories: pairwise classifiers and multiclass classifiers. The aim of a pairwise classifier is to separate one class from another one. Because of pairwise classifiers just train for discrimination between two classes, decision boundaries of them are simpler and more effective than those of multiclass classifiers.The main idea behind the proposed method is to focus classifier in the erroneous spaces of problem and use of pairwise classification concept instead of multiclass classification concept. Indeed although usage of pairwise classification concept instead of multiclass classification concept is not new, we propose a new pairwise classifier ensemble with a very lower order. In this paper, first the most confused classes are determined and then some ensembles of classifiers are created. The classifiers of each of these ensembles jointly work using majority weighting votes. The results of these ensembles

  18. Ensemble Data Mining Methods

    Data.gov (United States)

    National Aeronautics and Space Administration — Ensemble Data Mining Methods, also known as Committee Methods or Model Combiners, are machine learning methods that leverage the power of multiple models to achieve...

  19. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  20. LES SCEAUX DE CERTIFICATION DES SITES WEB : UN OUTIL DE CONFIANCE, OUTIL DE CONFUSION

    OpenAIRE

    Martel, Louise; St-Germain, René

    2002-01-01

    Avec l'évolution des technologies, les entreprises doivent s'adapter au nouveau concept de commerce électronique; les clients aussi. Comment garder leur confiance et ce, au bout des doigts. Ce texte présente un cadre conceptuel de la certification de conformité des sites Web ainsi qu'une typologie des sceaux de certification (labels) existants.

  1. L'action de tir à mi-distance en basket-ball : une approche technologique

    OpenAIRE

    Muguet,, Jean-Pierre

    2009-01-01

    Cette étude d'une action particulière du basket-ball a été conduite afin d'approfondir les conditions d'élaboration et de fonctionnement d'une démarche technique. Le sujet qui sert de support à cette exploration, le tir à mi-distance, a été choisi à la fois à cause de l'impossibilité de poursuivre un tel objectif en une seule étude pour l'ensemble du jeu, et parce qu'il en est une des actions typiques et néanmoins problématique dans le monde de l'intervention. La nécessité de différer l'opéra...

  2. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. PMID:27516599

  3. Neural Network Ensembles

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Salamon, Peter

    1990-01-01

    We propose several means for improving the performance an training of neural networks for classification. We use crossvalidation as a tool for optimizing network parameters and architecture. We show further that the remaining generalization error can be reduced by invoking ensembles of similar...... networks....

  4. Milan Kundera, Une rencontre

    Directory of Open Access Journals (Sweden)

    Céline Magain

    2009-10-01

    Full Text Available  « …rencontre de mes réflexions et de mes souvenirs ; de mes vieux thèmes (existentiels et esthétiques et mes vieux amours (Rabelais, Janacek, Fellini, Malaparte… » (p. 9 C’est sur ces mots que le célèbre auteur d’origine tchèque Milan Kundera introduit Une rencontre, son quatrième et dernier essai en français, qui réunit de nouveaux textes et des anciens, réactualisés ou incorporés dans de nouveaux écrits. Comme le titre l’indique, il s’agit bien de rencontre, au sens propre comme au fig...

  5. Ensemble Pulsar Time Scale

    CERN Document Server

    Rodin, Alexander E

    2010-01-01

    The algorithm of the ensemble pulsar time scale (PT$_{\\rm ens}$) based on the optimal Wiener filtration method has been proposed. This algorithm allows the separation of the contributions to the post-fit pulsar timing residuals of the atomic clock and pulsar itself. Filters were designed with the use of the cross-spectra of the timing residuals. The method has been applied to the timing data of six millisecond pulsars. Direct comparison with the classical method of the weighted average showed that use of the optimal Wiener filters before averaging allows noticeably to improve the fractional instability of the ensemble time scale. Application of the proposed method to the most stable millisecond pulsars with the fractional instability $\\sigma_z < 10^{-15}$ may improve the fractional instability of PT$_{\\rm ens}$ up to the level $\\sim 10^{-16}$.

  6. Ensemble Pulsar Time Scale

    Science.gov (United States)

    Yin, D. S.; Gao, Y. P.; Zhao, S. H.

    2016-05-01

    Millisecond pulsars can generate another type of time scale that is totally independent of the atomic time scale, because the physical mechanisms of the pulsar time scale and the atomic time scale are quite different from each other. Usually the pulsar timing observational data are not evenly sampled, and the internals between data points range from several hours to more than half a month. What's more, these data sets are sparse. And all these make it difficult to generate an ensemble pulsar time scale. Hence, a new algorithm to calculate the ensemble pulsar time scale is proposed. Firstly, we use cubic spline interpolation to densify the data set, and make the intervals between data points even. Then, we employ the Vondrak filter to smooth the data set, and get rid of high-frequency noise, finally adopt the weighted average method to generate the ensemble pulsar time scale. The pulsar timing residuals represent clock difference between the pulsar time and atomic time, and the high precision pulsar timing data mean the clock difference measurement between the pulsar time and atomic time with a high signal to noise ratio, which is fundamental to generate pulsar time. We use the latest released NANOGRAV (North American Nanohertz Observatory for Gravitational Waves) 9-year data set to generate the ensemble pulsar time scale. This data set is from the newest NANOGRAV data release, which includes 9-year observational data of 37 millisecond pulsars using the 100-meter Green Bank telescope and 305-meter Arecibo telescope. We find that the algorithm used in this paper can lower the influence caused by noises in timing residuals, and improve long-term stability of pulsar time. Results show that the long-term (> 1 yr) frequency stability of the pulsar time is better than 3.4×10-15.

  7. Effective Visualization of Temporal Ensembles.

    Science.gov (United States)

    Hao, Lihua; Healey, Christopher G; Bass, Steffen A

    2016-01-01

    An ensemble is a collection of related datasets, called members, built from a series of runs of a simulation or an experiment. Ensembles are large, temporal, multidimensional, and multivariate, making them difficult to analyze. Another important challenge is visualizing ensembles that vary both in space and time. Initial visualization techniques displayed ensembles with a small number of members, or presented an overview of an entire ensemble, but without potentially important details. Recently, researchers have suggested combining these two directions, allowing users to choose subsets of members to visualization. This manual selection process places the burden on the user to identify which members to explore. We first introduce a static ensemble visualization system that automatically helps users locate interesting subsets of members to visualize. We next extend the system to support analysis and visualization of temporal ensembles. We employ 3D shape comparison, cluster tree visualization, and glyph based visualization to represent different levels of detail within an ensemble. This strategy is used to provide two approaches for temporal ensemble analysis: (1) segment based ensemble analysis, to capture important shape transition time-steps, clusters groups of similar members, and identify common shape changes over time across multiple members; and (2) time-step based ensemble analysis, which assumes ensemble members are aligned in time by combining similar shapes at common time-steps. Both approaches enable users to interactively visualize and analyze a temporal ensemble from different perspectives at different levels of detail. We demonstrate our techniques on an ensemble studying matter transition from hadronic gas to quark-gluon plasma during gold-on-gold particle collisions. PMID:26529728

  8. Effective Visualization of Temporal Ensembles.

    Science.gov (United States)

    Hao, Lihua; Healey, Christopher G; Bass, Steffen A

    2016-01-01

    An ensemble is a collection of related datasets, called members, built from a series of runs of a simulation or an experiment. Ensembles are large, temporal, multidimensional, and multivariate, making them difficult to analyze. Another important challenge is visualizing ensembles that vary both in space and time. Initial visualization techniques displayed ensembles with a small number of members, or presented an overview of an entire ensemble, but without potentially important details. Recently, researchers have suggested combining these two directions, allowing users to choose subsets of members to visualization. This manual selection process places the burden on the user to identify which members to explore. We first introduce a static ensemble visualization system that automatically helps users locate interesting subsets of members to visualize. We next extend the system to support analysis and visualization of temporal ensembles. We employ 3D shape comparison, cluster tree visualization, and glyph based visualization to represent different levels of detail within an ensemble. This strategy is used to provide two approaches for temporal ensemble analysis: (1) segment based ensemble analysis, to capture important shape transition time-steps, clusters groups of similar members, and identify common shape changes over time across multiple members; and (2) time-step based ensemble analysis, which assumes ensemble members are aligned in time by combining similar shapes at common time-steps. Both approaches enable users to interactively visualize and analyze a temporal ensemble from different perspectives at different levels of detail. We demonstrate our techniques on an ensemble studying matter transition from hadronic gas to quark-gluon plasma during gold-on-gold particle collisions.

  9. Une perspective interactionniste

    Directory of Open Access Journals (Sweden)

    Joëlle Morrissette

    2010-02-01

    Full Text Available Cet article vise à montrer l’intérêt de puiser à la sociologie pour conduire des recherches dans le domaine de l’éducation. Plus précisément, il sera question de la contribution d’une perspective interactionniste pour appréhender un objet attaché à l’évaluation des apprentissages des élèves. Comme on le verra, s’inspirer en particulier d’auteurs attachés à la tradition de l’interactionnisme symbolique amène à se situer en marge des manières de dire et de faire habituelles des investigations portant sur cet objet, de la phase de problématisation à celle de l’analyse, au profit d’un point de vue (resocialisant et contextualisant. Pour illustrer le propos, je prendrai appui sur le format d’une recherche ayant documenté le savoir-faire d’un groupe d’enseignantes du primaire en matière d’évaluation formative, et ayant adopté une perspective interactionniste comme posture générale de recherche.An Interactionist PerspectiveAn Alternative Approach to Learning AssessmentThis article aims to show the usefulness of drawing from sociology to conduct research in the field of education. Specifically, it discusses the contribution of an interactionist perspective in understanding the objects attached to student learning assessment. As we shall see, drawing especially from authors working in the tradition of Symbolic Interactionism leads us outside the usual ways of thinking and doing in investigations related to assessment objects, from problematization to analysis, in favour of a (resocializing and contextualizing perspective. To illustrate this point, I will examine the format of a study documenting the expertise of a group of elementary school teachers with regard to formative assessment, and having an interactionist perspective as its basis of research.Una perspectiva interaccionista: otro punto de vista sobre la evaluación del aprendizajeEste artículo tiene como objetivo el demostrar el interés de

  10. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Hakon

    2016-06-14

    This work embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. The resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  11. Tibetan Song and Dance Ensemble

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    THE chief members of the TibetanSong and Dance Ensemble areTibetan,but also include Hui,Lhoba and Monba artists.This ensemble mainly performs Tibetan traditional music,dance and Tibetan opera.Programs can be divided into three categories,folk,traditional palace and monastery styles.The program of this ensemble includes the Tibetan symphony instrumental the Tibetan symphony instrumental suite "Ceremony in the Snowy Region."the palace dance "Karer"passages of the traditional Tibetan

  12. KID syndrome une cause de pachydermatologie

    OpenAIRE

    BOUDGHENE STAMBOULI, O.; BELBACHIR, A

    2012-01-01

    le KID syndrome est une dysplasie ectodermique rare,associant une erythrokeratodermie,une surdite et une keratine. Le Syndrome de Melkersson Rosenthal (SMR) (1) est une entité rare, caractérisée cliniquement par une triade (Macrochéilite, paralysie faciale périphérique, langue plicaturée) et histologiquement par la présence d’infiltrats dermiques granulomateux. Nous rapportons notre expérience sur ce syndrome où les différents traitements médicamenteux préconisés au long cou...

  13. PSO-Ensemble Demo Application

    DEFF Research Database (Denmark)

    2004-01-01

    Within the framework of the PSO-Ensemble project (FU2101) a demo application has been created. The application use ECMWF ensemble forecasts. Two instances of the application are running; one for Nysted Offshore and one for the total production (except Horns Rev) in the Eltra area. The output is...

  14. Representative Ensembles in Statistical Mechanics

    OpenAIRE

    V. I. YUKALOV

    2007-01-01

    The notion of representative statistical ensembles, correctly representing statistical systems, is strictly formulated. This notion allows for a proper description of statistical systems, avoiding inconsistencies in theory. As an illustration, a Bose-condensed system is considered. It is shown that a self-consistent treatment of the latter, using a representative ensemble, always yields a conserving and gapless theory.

  15. Botnet analysis using ensemble classifier

    Directory of Open Access Journals (Sweden)

    Anchit Bijalwan

    2016-09-01

    Full Text Available This paper analyses the botnet traffic using Ensemble of classifier algorithm to find out bot evidence. We used ISCX dataset for training and testing purpose. We extracted the features of both training and testing datasets. After extracting the features of this dataset, we bifurcated these features into two classes, normal traffic and botnet traffic and provide labelling. Thereafter using modern data mining tool, we have applied ensemble of classifier algorithm. Our experimental results show that the performance for finding bot evidence using ensemble of classifiers is better than single classifier. Ensemble based classifiers perform better than single classifier by either combining powers of multiple algorithms or introducing diversification to the same classifier by varying input in bot analysis. Our results are showing that by using voting method of ensemble based classifier accuracy is increased up to 96.41% from 93.37%.

  16. Résolution du problème de car-sequencing à l'aide d'une approche de type FC

    OpenAIRE

    Boivin, Simon; Gravel, Marc; Krajecki, Michaël; Gagné, Caroline

    2005-01-01

    http://www710.univ-lyon1.fr/~csolnon Le problème de car-sequencing consiste à déterminer l'ordre dans lequel un ensemble de voitures seront fabriquées sur une chaîne d'assemblage. Certaines voitures comprennent des options telles que le toit ouvrant, l'air climatisé ou autres pour lesquelles une charge de travail additionnelle est requise à un poste particulier de la chaîne. Pour chacune de ces voitures difficiles, la chaîne d'assemblage possède une capacité maximale indiquant le nombre de...

  17. On Ensemble Nonlinear Kalman Filtering with Symmetric Analysis Ensembles

    KAUST Repository

    Luo, Xiaodong

    2010-09-19

    The ensemble square root filter (EnSRF) [1, 2, 3, 4] is a popular method for data assimilation in high dimensional systems (e.g., geophysics models). Essentially the EnSRF is a Monte Carlo implementation of the conventional Kalman filter (KF) [5, 6]. It is mainly different from the KF at the prediction steps, where it is some ensembles, rather then the means and covariance matrices, of the system state that are propagated forward. In doing this, the EnSRF is computationally more efficient than the KF, since propagating a covariance matrix forward in high dimensional systems is prohibitively expensive. In addition, the EnSRF is also very convenient in implementation. By propagating the ensembles of the system state, the EnSRF can be directly applied to nonlinear systems without any change in comparison to the assimilation procedures in linear systems. However, by adopting the Monte Carlo method, the EnSRF also incurs certain sampling errors. One way to alleviate this problem is to introduce certain symmetry to the ensembles, which can reduce the sampling errors and spurious modes in evaluation of the means and covariances of the ensembles [7]. In this contribution, we present two methods to produce symmetric ensembles. One is based on the unscented transform [8, 9], which leads to the unscented Kalman filter (UKF) [8, 9] and its variant, the ensemble unscented Kalman filter (EnUKF) [7]. The other is based on Stirling’s interpolation formula (SIF), which results in the divided difference filter (DDF) [10]. Here we propose a simplified divided difference filter (sDDF) in the context of ensemble filtering. The similarity and difference between the sDDF and the EnUKF will be discussed. Numerical experiments will also be conducted to investigate the performance of the sDDF and the EnUKF, and compare them to a well‐established EnSRF, the ensemble transform Kalman filter (ETKF) [2].

  18. No certificate, no chocolate

    CERN Multimedia

    Computer Security Team

    2013-01-01

    Are you already ready to use “certificates” to log into CERN or to connect to the global “eduroam” wireless network? No, I am not talking about your birth certificate, medical certificates or academic certificates. I am referring to “certificates” used for authentication where you would usually use a password.   These digital certificates are a valid alternative to cumbersome passwords. Like the aforementioned personal certificates, a digital certificate is an official document that proves who you are or your qualifications. Your personal digital CERN certificate is tied to your digital identity at CERN. In that respect, a digital certificate is like a password. It is a credential that you must not share with anybody else! With your digital certificate, I can impersonate you and take over your mailbox, your web sessions and more… Digital certificates bind your digital identity to a public/private-key infrastructu...

  19. The Ensembl gene annotation system.

    Science.gov (United States)

    Aken, Bronwen L; Ayling, Sarah; Barrell, Daniel; Clarke, Laura; Curwen, Valery; Fairley, Susan; Fernandez Banet, Julio; Billis, Konstantinos; García Girón, Carlos; Hourlier, Thibaut; Howe, Kevin; Kähäri, Andreas; Kokocinski, Felix; Martin, Fergal J; Murphy, Daniel N; Nag, Rishi; Ruffier, Magali; Schuster, Michael; Tang, Y Amy; Vogel, Jan-Hinnerk; White, Simon; Zadissa, Amonida; Flicek, Paul; Searle, Stephen M J

    2016-01-01

    The Ensembl gene annotation system has been used to annotate over 70 different vertebrate species across a wide range of genome projects. Furthermore, it generates the automatic alignment-based annotation for the human and mouse GENCODE gene sets. The system is based on the alignment of biological sequences, including cDNAs, proteins and RNA-seq reads, to the target genome in order to construct candidate transcript models. Careful assessment and filtering of these candidate transcripts ultimately leads to the final gene set, which is made available on the Ensembl website. Here, we describe the annotation process in detail.Database URL: http://www.ensembl.org/index.html. PMID:27337980

  20. Un kyste hydatique osseux: une localisation rare au niveau de l’os iliaque

    Science.gov (United States)

    Nhamoucha, Yassine; Alaoui, Othmane; Doumbia, Aliou; Oukhoya, Mohammed; Abdellaoui, Hicham; Tazi, Mohammed; Chater, Lamyae; Atarraf, Karima; Arroud, Mounir; Afifi, Abderahman

    2016-01-01

    L'hydatidose est une affection parasitaire liée au développement chez l'homme de la forme larvaire d'un cestode, à savoir un tænia de très petite taille dénommé Echinococcus Granulosus. Cette anthropozoonose présente une diversité de formes anatomoradiologiques lié aux nombreux aspects topographiques et évolutifs des kystes. L'hydatidose osseuse est rare, elle ne représente que 0,9 à 2,5% de l'ensemble des localisations. Nous rapportons l'observation d'un enfant de 9 ans, qui a été admis chez nous pour une boiterie fébrile avec une masse au niveau de la fosse iliaque droite, révélant un kyste hydatique au dépend de l'os iliaque. Le bilan lésionnel avait objectivé un kyste hydatique de l'os iliaque avec extension aux parties molles adjacentes. Le traitement chirurgical conclu a un kyste surinfecté d'ou la réalisation d'une exérèse chirurgicale du kyste avec drainage. L'ostéopathie hydatique est infiltrante, diffuse, lente et progressive, ce qui rend le diagnostic tardif et qui compromet la qualité du traitement. PMID:27800081

  1. Certification for sugarcane production processes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Camila Ortolan F. de; Walter, Arnaldo

    2012-07-01

    This chapter concerns with the meaning of certification, sustainability of bioenergy, sustainability initiatives and certification schemes, certification tendencies in Brazil, and the challenge for fulfilling criteria.

  2. Diurnal Ensemble Surface Meteorology Statistics

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excel file containing diurnal ensemble statistics of 2-m temperature, 2-m mixing ratio and 10-m wind speed. This Excel file contains figures for Figure 2 in the...

  3. Planification de mission pour une patrouille de micro-drones

    OpenAIRE

    Huard, Pierre-Selim; Barnier, Nicolas; Brisset, Pascal; Verfaillie, Gérard

    2009-01-01

    Le problème de planification de mission en ligne pour une patrouille de mini-drones est un problème d'optimisation fortement combinatoire. Il s'agit d'affecter l'ensemble des objectifs de la mission aux drones de la patrouille et d'ordonner leur exécution pour que la patrouille finisse l'intégralité de la mission au plus tôt. Pour faire face aux incertitudes liées à l'exécution de la mission, les solutions sont recalculées de façon réactive si nécessaire pendant la mission. Dans cet article n...

  4. The entropy of network ensembles

    OpenAIRE

    Bianconi, Ginestra

    2008-01-01

    In this paper we generalize the concept of random networks to describe networks with non trivial features by a statistical mechanics approach. This framework is able to describe ensembles of undirected, directed as well as weighted networks. These networks might have not trivial community structure or, in the case of networks embedded in a given space, non trivial distance dependence of the link probability. These ensembles are characterized by their entropy which evaluate the cardinality of ...

  5. Similarity measures for protein ensembles

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Ferkinghoff-Borg, Jesper

    2009-01-01

    Analyses of similarities and changes in protein conformation can provide important information regarding protein function and evolution. Many scores, including the commonly used root mean square deviation, have therefore been developed to quantify the similarities of different protein conformations...... a synthetic example from molecular dynamics simulations. We then apply the algorithms to revisit the problem of ensemble averaging during structure determination of proteins, and find that an ensemble refinement method is able to recover the correct distribution of conformations better than standard single...

  6. Deformed Ginibre ensembles and integrable systems

    Energy Technology Data Exchange (ETDEWEB)

    Orlov, A.Yu., E-mail: orlovs@ocean.ru

    2014-01-17

    We consider three Ginibre ensembles (real, complex and quaternion-real) with deformed measures and relate them to known integrable systems by presenting partition functions of these ensembles in form of fermionic expectation values. We also introduce double deformed Dyson–Wigner ensembles and compare their fermionic representations with those of Ginibre ensembles.

  7. Histoire d'une dation

    OpenAIRE

    Bernard, Maurice

    2011-01-01

    L’une des qualités dont Alfred Sauvy a fait preuve tout au long de sa vie me semble être la lucidité, je crois que l’histoire de la dation le montre bien. Il était en effet convaincu que les 1800 livres qu’il avait au cours de sa longue vie rassemblés, lus, étudiés, annotés auraient une grande valeur pour les historiens intéressés par la génèse de la démographie moderne et par son oeuvre d’économiste, de sociologue. Vers la fin de sa vie il était à juste titré soucieux d’éviter la dispersion...

  8. Valorisation d'une prospection électrique pour établir une carte d'épaisseur du sol

    OpenAIRE

    Ndjiba Mitombo, Daril

    2013-01-01

    Dans le projet cadre du projet CAREX de l’INRA, le travail présenté dans ce document a pour objectif d’étudier et de comparer deux approches (non spatial et spatial) de spatialisation de l’épaisseur du sol (variable d’intérêt), à partir de mesures de la résistivité électrique du sol (variable auxiliaire). Une prospection électrique a été réalisée sur l’ensemble du site expérimental de l’INRA d’Epoisses à partir du dispositif tracté ARP, qui mesure la résistivité pour trois profondeurs d’inves...

  9. L’action française: une matrice européenne et transatlantique des droites radicales?

    Directory of Open Access Journals (Sweden)

    Olivier DARD

    2013-05-01

    Full Text Available L’action française et le maurrassisme sont indissociables de la figure de maurras. En même temps, ils la dépassent. L’action française renvoie à une réalité polymorphe articulée autour de trois piliers: une doctrine, un quotidien et une ligue. Cet ensemble a eu une influence incontestable non seulement en France mais aussi à l’étranger. Une étude sur ce dernier point permet de mettre en lumière une chronologie sensiblement différente de celle qui a été proposée pour la France. En même temps, l’examen des vecteurs de pénétration et des transferts politiques et culturels à l’œuvre font découvrir les différentes façons d’être maurrassien de l’Europe aux Amériques.

  10. Ensemble algorithms in reinforcement learning.

    Science.gov (United States)

    Wiering, Marco A; van Hasselt, Hado

    2008-08-01

    This paper describes several ensemble methods that combine multiple different reinforcement learning (RL) algorithms in a single agent. The aim is to enhance learning speed and final performance by combining the chosen actions or action probabilities of different RL algorithms. We designed and implemented four different ensemble methods combining the following five different RL algorithms: Q-learning, Sarsa, actor-critic (AC), QV-learning, and AC learning automaton. The intuitively designed ensemble methods, namely, majority voting (MV), rank voting, Boltzmann multiplication (BM), and Boltzmann addition, combine the policies derived from the value functions of the different RL algorithms, in contrast to previous work where ensemble methods have been used in RL for representing and learning a single value function. We show experiments on five maze problems of varying complexity; the first problem is simple, but the other four maze tasks are of a dynamic or partially observable nature. The results indicate that the BM and MV ensembles significantly outperform the single RL algorithms. PMID:18632380

  11. Estimating preselected and postselected ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Massar, Serge [Laboratoire d' Information Quantique, C.P. 225, Universite libre de Bruxelles (U.L.B.), Av. F. D. Rooselvelt 50, B-1050 Bruxelles (Belgium); Popescu, Sandu [H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Hewlett-Packard Laboratories, Stoke Gifford, Bristol BS12 6QZ (United Kingdom)

    2011-11-15

    In analogy with the usual quantum state-estimation problem, we introduce the problem of state estimation for a pre- and postselected ensemble. The problem has fundamental physical significance since, as argued by Y. Aharonov and collaborators, pre- and postselected ensembles are the most basic quantum ensembles. Two new features are shown to appear: (1) information is flowing to the measuring device both from the past and from the future; (2) because of the postselection, certain measurement outcomes can be forced never to occur. Due to these features, state estimation in such ensembles is dramatically different from the case of ordinary, preselected-only ensembles. We develop a general theoretical framework for studying this problem and illustrate it through several examples. We also prove general theorems establishing that information flowing from the future is closely related to, and in some cases equivalent to, the complex conjugate information flowing from the past. Finally, we illustrate our approach on examples involving covariant measurements on spin-1/2 particles. We emphasize that all state-estimation problems can be extended to the pre- and postselected situation. The present work thus lays the foundations of a much more general theory of quantum state estimation.

  12. CME Ensemble Forecasting - A Primer

    Science.gov (United States)

    Pizzo, V. J.; de Koning, C. A.; Cash, M. D.; Millward, G. H.; Biesecker, D. A.; Codrescu, M.; Puga, L.; Odstrcil, D.

    2014-12-01

    SWPC has been evaluating various approaches for ensemble forecasting of Earth-directed CMEs. We have developed the software infrastructure needed to support broad-ranging CME ensemble modeling, including composing, interpreting, and making intelligent use of ensemble simulations. The first step is to determine whether the physics of the interplanetary propagation of CMEs is better described as chaotic (like terrestrial weather) or deterministic (as in tsunami propagation). This is important, since different ensemble strategies are to be pursued under the two scenarios. We present the findings of a comprehensive study of CME ensembles in uniform and structured backgrounds that reveals systematic relationships between input cone parameters and ambient flow states and resulting transit times and velocity/density amplitudes at Earth. These results clearly indicate that the propagation of single CMEs to 1 AU is a deterministic process. Thus, the accuracy with which one can forecast the gross properties (such as arrival time) of CMEs at 1 AU is determined primarily by the accuracy of the inputs. This is no tautology - it means specifically that efforts to improve forecast accuracy should focus upon obtaining better inputs, as opposed to developing better propagation models. In a companion paper (deKoning et al., this conference), we compare in situ solar wind data with forecast events in the SWPC operational archive to show how the qualitative and quantitative findings presented here are entirely consistent with the observations and may lead to improved forecasts of arrival time at Earth.

  13. Ensemble Equivalence for Distinguishable Particles

    Directory of Open Access Journals (Sweden)

    Antonio Fernández-Peralta

    2016-07-01

    Full Text Available Statistics of distinguishable particles has become relevant in systems of colloidal particles and in the context of applications of statistical mechanics to complex networks. In this paper, we present evidence that a commonly used expression for the partition function of a system of distinguishable particles leads to huge fluctuations of the number of particles in the grand canonical ensemble and, consequently, to nonequivalence of statistical ensembles. We will show that the alternative definition of the partition function including, naturally, Boltzmann’s correct counting factor for distinguishable particles solves the problem and restores ensemble equivalence. Finally, we also show that this choice for the partition function does not produce any inconsistency for a system of distinguishable localized particles, where the monoparticular partition function is not extensive.

  14. Excitation energies from ensemble DFT

    Science.gov (United States)

    Borgoo, Alex; Teale, Andy M.; Helgaker, Trygve

    2015-12-01

    We study the evaluation of the Gross-Oliveira-Kohn expression for excitation energies E1-E0=ɛ1-ɛ0+∂E/xc,w[ρ] ∂w | ρ =ρ0. This expression gives the difference between an excitation energy E1 - E0 and the corresponding Kohn-Sham orbital energy difference ɛ1 - ɛ0 as a partial derivative of the exchange-correlation energy of an ensemble of states Exc,w[ρ]. Through Lieb maximisation, on input full-CI density functions, the exchange-correlation energy is evaluated accurately and the partial derivative is evaluated numerically using finite difference. The equality is studied numerically for different geometries of the H2 molecule and different ensemble weights. We explore the adiabatic connection for the ensemble exchange-correlation energy. The latter may prove useful when modelling the unknown weight dependence of the exchange-correlation energy.

  15. Ensemble teleportation under suboptimal conditions

    International Nuclear Information System (INIS)

    The possibility of teleportation is certainly the most interesting consequence of quantum non-separability. In the present paper, the feasibility of teleportation is examined on the basis of the rigorous ensemble interpretation of quantum mechanics if non-ideal constraints are imposed on the teleportation scheme. Importance is attached both to the case of noisy Einstein-Podolsky-Rosen (EPR) ensembles and to the conditions under which automatic teleportation is still possible. The success of teleportation is discussed using a new fidelity measure which avoids the weaknesses of previous proposals

  16. The Partition Ensemble Fallacy Fallacy

    CERN Document Server

    Nemoto, K; Nemoto, Kae; Braunstein, Samuel L.

    2002-01-01

    The Partition Ensemble Fallacy was recently applied to claim no quantum coherence exists in coherent states produced by lasers. We show that this claim relies on an untestable belief of a particular prior distribution of absolute phase. One's choice for the prior distribution for an unobservable quantity is a matter of `religion'. We call this principle the Partition Ensemble Fallacy Fallacy. Further, we show an alternative approach to construct a relative-quantity Hilbert subspace where unobservability of certain quantities is guaranteed by global conservation laws. This approach is applied to coherent states and constructs an approximate relative-phase Hilbert subspace.

  17. Une séparation

    OpenAIRE

    Videau, André

    2013-01-01

    Sur les écrans étroitement surveillés de la République islamique d’Iran, les plus célèbres réalisateurs (Kiarostami, Makhmalbaf, Panahi…) ont pratiqué les techniques du contournement, du transfert, de l’allusion plus ou moins transparente. Il n’était pas pensable de s’attaquer de plein fouet aux problèmes d’une société adulte et contemporaine. On voilait les sentiments comme les femmes pour ne pas courroucer la censure. Il incombait aux enfants de signifier les relations humaines. L’exercice ...

  18. Wiktor Stoczkowski, Des hommes, des dieux et des extraterrestres. Ethnologie d’une croyance moderne

    OpenAIRE

    Lepoutre, David

    2006-01-01

    Voici un ouvrage qui nous fait entrer de plain-pied dans une subculture contemporaine généralement perçue comme marginale et qui s’avère pourtant être d’une importance sociale considérable. Il s’agit de l’univers, exotique s’il en est, des parasciences et de la pensée occultiste. Le lecteur curieux y trouvera un ensemble de développements remarquablement bien documentés et ordonnés sur un certain nombre de sujets et de thèmes liés à cette pensée contemporaine dont les ramifications tentaculai...

  19. Pour une véritable éducation esthétique

    OpenAIRE

    Troyas, Alain

    2013-01-01

    L'actuel programme officiel concernant l'Enseignement des Arts Plastiques est inadapté. Il ne prépare pas tous les élèves à participer à la construction de l'ensemble de l'environnement visuel. Comment y parvenir? Par l'introduction d'un enseignement fondé sur les Sciences humaines. Dans la  perspective d'une pédagogie différenciée, un tel parcours s'articulerait certes au monde des images mais aussi autour d'une culture générale où les psychologies autant que les sociologies, l'esthétique ou...

  20. Ensemble algorithms in reinforcement learning

    NARCIS (Netherlands)

    Wiering, Marco A; van Hasselt, Hado

    2008-01-01

    This paper describes several ensemble methods that combine multiple different reinforcement learning (RL) algorithms in a single agent. The aim is to enhance learning speed and final performance by combining the chosen actions or action probabilities of different RL algorithms. We designed and imple

  1. Multimodel ensembles of wheat growth

    DEFF Research Database (Denmark)

    Martre, Pierre; Wallach, Daniel; Asseng, Senthold;

    2015-01-01

    Crop models of crop growth are increasingly used to quantify the impact of global changes due to climate or crop management. Therefore, accuracy of simulation results is a major concern. Studies with ensembles of crop models can give valuable information about model accuracy and uncertainty, but ...

  2. Global Ensemble Forecast System (GEFS) [1 Deg.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Ensemble Forecast System (GEFS) is a weather forecast model made up of 21 separate forecasts, or ensemble members. The National Centers for Environmental...

  3. Une reine en Arabie du Sud ?

    Directory of Open Access Journals (Sweden)

    Mounir Arbach

    2004-10-01

    Full Text Available Une inscription inédite al-Jawf.04.32, provenant vraisemblablement de Barâqish et ses environs, a été découverte lors de fouilles clandestines. Elle date du VIIe av. J.-C. L’auteur, une femme a fait une dédicace au Dieu Nkrh, au jour où elle a régné sur Nt‘htn. Bien que cette nouvelle inscription soit courte, de deux lignes, son importance réside dans le fait qu’elle mentionne pour la première fois une femme régnante sur une région non identifiée. Cette découverte relance le débat sur l’histoire de la légendaire reine de Saba, Bilqîs.

  4. Une reine en Arabie du Sud ?

    OpenAIRE

    Mounir Arbach

    2007-01-01

    Une inscription inédite al-Jawf.04.32, provenant vraisemblablement de Barâqish et ses environs, a été découverte lors de fouilles clandestines. Elle date du VIIe av. J.-C. L’auteur, une femme a fait une dédicace au Dieu Nkrh, au jour où elle a régné sur Nt‘htn. Bien que cette nouvelle inscription soit courte, de deux lignes, son importance réside dans le fait qu’elle mentionne pour la première fois une femme régnante sur une région non identifiée. Cette découverte relance le débat sur l’histo...

  5. Jalons pour une anthropologie de l’éthique entrepreneuriale en Asie du Sud-Est

    OpenAIRE

    Gallenga, Ghislaine; Soldani, Jérôme

    2013-01-01

    L’éthique entrepreneuriale est une notion largement mobilisée dans le milieu des affaires et des entreprises en Asie du Sud-Est où elle est présentée le plus souvent comme un ensemble de préceptes moraux, idéologiques ou religieux que les acteurs locaux rassemblent sous le vocable « valeurs asiatiques ». L’objet de cette introduction est de replacer ces valeurs dans le contexte de l’entreprise à partir de quelques travaux fondateurs de ce sujet en Asie du Sud-Est. Nous verrons que le plus sou...

  6. Estimation du volume des ensembles d'excursion d'un processus Gaussien par Krigeage intrinsèque

    OpenAIRE

    Vazquez, Emmanuel; Piera-Martinez, Miguel

    2007-01-01

    Estimer une probabilité de défaillance d'un système entrée-sortie à partir d'observations ponctuelles de celui-ci est un problème important pour le monde industriel. Une approche possible consiste à modéliser le système comme la réalisation d'un processus aléatoire et de s'intéresser au volume d'excursion de ce processus. Soit $\\xi$ un processus aléatoire gaussien et $\\abs{A_u(\\xi)}$ le volume de l'ensemble d'excursion de $\\xi$ au dessus d'un seuil $u$ sous une mesure de probabilité $\\mu$. L'...

  7. La crise du vivre-ensemble

    DEFF Research Database (Denmark)

    Schultz, Nils Voisin

    2014-01-01

    chance pour la France à condition que le dialogue interculturel soit renforcé et que l’idée d’une culture française y garde sa place, elle reste pour Millet une impossibilité. L’enjeu de l’analyse est de dévoiler la capacité des discours à générer par l’affectivité une peur capable d’intensifier l...

  8. Spectral diagonal ensemble Kalman filters

    CERN Document Server

    Kasanický, Ivan; Vejmelka, Martin

    2015-01-01

    A new type of ensemble Kalman filter is developed, which is based on replacing the sample covariance in the analysis step by its diagonal in a spectral basis. It is proved that this technique improves the aproximation of the covariance when the covariance itself is diagonal in the spectral basis, as is the case, e.g., for a second-order stationary random field and the Fourier basis. The method is extended by wavelets to the case when the state variables are random fields, which are not spatially homogeneous. Efficient implementations by the fast Fourier transform (FFT) and discrete wavelet transform (DWT) are presented for several types of observations, including high-dimensional data given on a part of the domain, such as radar and satellite images. Computational experiments confirm that the method performs well on the Lorenz 96 problem and the shallow water equations with very small ensembles and over multiple analysis cycles.

  9. Symanzik flow on HISQ ensembles

    CERN Document Server

    Bazavov, A; Brown, N; DeTar, C; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    We report on a scale determination with gradient-flow techniques on the $N_f = 2 + 1 + 1$ HISQ ensembles generated by the MILC collaboration. The lattice scale $w_0/a$, originally proposed by the BMW collaboration, is computed using Symanzik flow at four lattice spacings ranging from 0.15 to 0.06 fm. With a Taylor series ansatz, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. We give a preliminary determination of the scale $w_0$ in physical units, along with associated systematic errors, and compare with results from other groups. We also present a first estimate of autocorrelation lengths as a function of flowtime for these ensembles.

  10. Simple Deep Random Model Ensemble

    OpenAIRE

    ZHANG, XIAO-LEI; Wu, Ji

    2013-01-01

    Representation learning and unsupervised learning are two central topics of machine learning and signal processing. Deep learning is one of the most effective unsupervised representation learning approach. The main contributions of this paper to the topics are as follows. (i) We propose to view the representative deep learning approaches as special cases of the knowledge reuse framework of clustering ensemble. (ii) We propose to view sparse coding when used as a feature encoder as the consens...

  11. Ensemble Modeling of Cancer Metabolism

    Directory of Open Access Journals (Sweden)

    Tahmineh eKhazaei

    2012-05-01

    Full Text Available The metabolic behaviour of cancer cells is adapted to meet their proliferative needs, with notable changes such as enhanced lactate secretion and glucose uptake rates. In this work, we use the Ensemble Modeling (EM framework to gain insight and predict potential drug targets for tumour cells. EM generates a set of models which span the space of kinetic parameters that are constrained by thermodynamics. Perturbation data based on known targets are used to screen the entire ensemble of models to obtain a sub-set, which is increasingly predictive. EM allows for incorporation of regulatory information and captures the behaviour of enzymatic reactions at the molecular level by representing reactions in the elementary reaction form. In this study, a metabolic network consisting of 58 reactions is considered and accounts for glycolysis, the pentose phosphate pathway, lipid metabolism, amino acid metabolism, and includes allosteric regulation of key enzymes. Experimentally measured intracellular and extracellular metabolite concentrations are used for developing the ensemble of models along with information on established drug targets. The resulting models predicted transaldolase (TALA and succinyl-CoA ligase (SUCOAS1m to cause a significant reduction in growth rate when repressed, relative to currently known drug targets. Furthermore, the results suggest that the synergetic repression of transaldolase and glycine hydroxymethyltransferase (GHMT2r will lead to a three-fold decrease in growth rate compared to the repression of single enzyme targets.

  12. Ensemble learning incorporating uncertain registration.

    Science.gov (United States)

    Simpson, Ivor J A; Woolrich, Mark W; Andersson, Jesper L R; Groves, Adrian R; Schnabel, Julia A

    2013-04-01

    This paper proposes a novel approach for improving the accuracy of statistical prediction methods in spatially normalized analysis. This is achieved by incorporating registration uncertainty into an ensemble learning scheme. A probabilistic registration method is used to estimate a distribution of probable mappings between subject and atlas space. This allows the estimation of the distribution of spatially normalized feature data, e.g., grey matter probability maps. From this distribution, samples are drawn for use as training examples. This allows the creation of multiple predictors, which are subsequently combined using an ensemble learning approach. Furthermore, extra testing samples can be generated to measure the uncertainty of prediction. This is applied to separating subjects with Alzheimer's disease from normal controls using a linear support vector machine on a region of interest in magnetic resonance images of the brain. We show that our proposed method leads to an improvement in discrimination using voxel-based morphometry and deformation tensor-based morphometry over bootstrap aggregating, a common ensemble learning framework. The proposed approach also generates more reasonable soft-classification predictions than bootstrap aggregating. We expect that this approach could be applied to other statistical prediction tasks where registration is important. PMID:23288332

  13. Vers une Didactique de l'Informatique

    OpenAIRE

    Caraballo, Silvina; Cicala, Rosa

    2006-01-01

    Le sujet de cet article est une recherche ayant pour objet l'étude de la Didactique de l'Informatique. En partant d'une brève description de la place qu'occupe actuellement l'informatique dans l'enseignement secondaire, nous exposons quelques conditions nécessaires pour réaliser une analyse épistémologique et didactique des contenus qui devraient être enseignés. Notre analyse se limite aux établissements secondaires publics de la Province de Buenos Aires.D'abord, nous envisageons l'analyse ép...

  14. Comparaison de populations de carpe commune (Cyprinus carpio à taille commerciale : intérêt d'une approche globale

    Directory of Open Access Journals (Sweden)

    PEREIRA V.

    1999-07-01

    Une discrimination géographique des populations est possible mais elle repose sur une approche globale intégrant l'ensemble des paramètres. Les différences semblent essentiellement liées aux conditions environnementales et permettent de distinguer les lots issus des régions où l'élevage est plus intensif et traditionnellement centré sur la carpe (Dombes, Forez, Lorraine et les lots correspondant à un élevage plus extensif et davantage orienté vers le marché du repeuplement (Allier, Brenne, Poitou-Charentes.

  15. Persuasion et promotion d’une idée:le cas des ‘meilleures pratiques’ de gouvernance en Allemagne

    OpenAIRE

    Peter Wirtz

    2005-01-01

    (VF)Depuis le milieu des années 1990, un ensemble d’idées portant sur les « meilleures pratiques » de gouvernance se diffuse à travers le monde sous la forme de codes de bonne conduite. Ces derniers affichent une remarquable convergence des principales recommandations, qui s’inspirent d’une approche essentiellement disciplinaire et actionnariale de la gouvernance. Le présent article s’interroge sur les raisons du succès des « meilleures pratiques » de gouvernance auprès de l’opinion publique....

  16. Notes et Solutions de Quelques Exercices du Livre: Th\\'eorie des Ensembles de N. Bourbaki

    CERN Document Server

    Darkaoui, Mohssin Zarouali

    2011-01-01

    These notes provide an opportunity to discover the beauty of Bourbaki set theory, and I hope that they will facilitate the task to those who find it difficult to read this book, one of the most critical elements of the mathematics of Bourbaki. ---- Ces notes constituent une occasion pour d\\'ecouvrir la beaut\\'e de la th\\'eorie des ensembles de Bourbaki, et j'esp\\`ere qu'elles faciliteront la t\\^ache \\`a ceux qui ont trouv\\'e des difficult\\'es en lisant ce livre qui est l'un des plus critiqu\\'e des \\'el\\'ements de math\\'ematique de Bourbaki.

  17. Optimally choosing small ensemble members to produce robust climate simulations

    International Nuclear Information System (INIS)

    This study examines the subset climate model ensemble size required to reproduce certain statistical characteristics from a full ensemble. The ensemble characteristics examined are the root mean square error, the ensemble mean and standard deviation. Subset ensembles are created using measures that consider the simulation performance alone or include a measure of simulation independence relative to other ensemble members. It is found that the independence measure is able to identify smaller subset ensembles that retain the desired full ensemble characteristics than either of the performance based measures. It is suggested that model independence be considered when choosing ensemble subsets or creating new ensembles. (letter)

  18. Mertens André, Une aventure urbanistique

    Directory of Open Access Journals (Sweden)

    Xavier Leloup

    2011-03-01

    Full Text Available L’objectif de l’ouvrage est de produire un effort de réflexion et de synthèse en vue de conserver les acquis d’une expérience “atypique”, celle de Louvain-la-Neuve, rare exemple de création d’une ville nouvelle par une autorité d’enseignement privé (l’Uni­versité catholique de Louvain, construite en réaction à des événements politiques particuliers. L’intention était de créer un environnement propice à une université en évitant de l’isoler du reste de la société. Il fallait aussi mettre à di...

  19. Certification for Information Brokers.

    Science.gov (United States)

    Sawyer, Deborah C.

    1995-01-01

    The future of the information broker business depends on certification. Some obstacles are lack of commonality, control, a professional title, and time. Core competencies (ethics, professional conduct, and client care) and specialties could determine certification criteria, and a grace period for phasing in established brokers could be initiated.…

  20. Une typologie archétypale des intentions discursives pour la mythanalyse

    Directory of Open Access Journals (Sweden)

    Andrés Dávila

    2014-12-01

    Full Text Available Traditionnellement, les analyses de discours se concentrent sur la description des structures et des réseaux socio-sémantiques grâce, entre autres techniques, à l'utilisation d'outils de statistiques textuelles. Dans cet article, nous proposons une démarche alternative qui positionne l'analyse en amont du discours et qui privilégie les éléments constitutifs d’un mythe comme une construction discursive. Se concentrer sur l'intention discursive permet d’appréhender différemment l’étude du discours portée par un mythe en rendant possible le déchiffrement de ses antécédents. Notre démarche vise à réaliser une typologie archétypale des intentions discursives pouvant expliquer l’origine des mythes. L'intention exprimée se réfère à un système de connaissances et de valeurs et vise à satisfaire des besoins précis. La typologie archétypale des intentions discursives émerge de l'ensemble des combinaisons possibles de trois types de connaissances – empiriques, scientifiques et intuitives – de trois types de valeurs – individuelles, contextuelles et universelles – et de trois types de besoins – physiques, sociaux et transcendantaux. Un discours/mythe n’est pas restreint à un seul archétype de la typologie proposée, il est le résultat d’une prioritisation de différents types de besoins, de connaissances, et des valeurs dans une combinaison unique et individuelle. Une telle typologie permettrait non seulement la description des intentions discursives constitutives des mythes mais aussi l'examen des tendances dominantes au sein d'une organisation ou d'un corps de métier, ou dans la société. Ce modèle est actuellement utilisé pour apparier des personnes indécises quant à leur orientation professionnelle à des métiers, sur la base d'un inventaire des intentions discursives déclarées.

  1. Wind Power Prediction using Ensembles

    DEFF Research Database (Denmark)

    Giebel, Gregor; Badger, Jake; Landberg, Lars;

    2005-01-01

    offshore wind farm and the whole Jutland/Funen area. The utilities used these forecasts for maintenance planning, fuel consumption estimates and over-the-weekend trading on the Leipzig power exchange. Othernotable scientific results include the better accuracy of forecasts made up from a simple...... superposition of two NWP provider (in our case, DMI and DWD), an investigation of the merits of a parameterisation of the turbulent kinetic energy within thedelivered wind speed forecasts, and the finding that a “naïve” downscaling of each of the coarse ECMWF ensemble members with higher resolution HIRLAM did...

  2. Gibbs Ensembles of Nonintersecting Paths

    CERN Document Server

    Borodin, Alexei

    2008-01-01

    We consider a family of determinantal random point processes on the two-dimensional lattice and prove that members of our family can be interpreted as a kind of Gibbs ensembles of nonintersecting paths. Examples include probability measures on lozenge and domino tilings of the plane, some of which are non-translation-invariant. The correlation kernels of our processes can be viewed as extensions of the discrete sine kernel, and we show that the Gibbs property is a consequence of simple linear relations satisfied by these kernels. The processes depend on infinitely many parameters, which are closely related to parametrization of totally positive Toeplitz matrices.

  3. A Localized Ensemble Kalman Smoother

    Science.gov (United States)

    Butala, Mark D.

    2012-01-01

    Numerous geophysical inverse problems prove difficult because the available measurements are indirectly related to the underlying unknown dynamic state and the physics governing the system may involve imperfect models or unobserved parameters. Data assimilation addresses these difficulties by combining the measurements and physical knowledge. The main challenge in such problems usually involves their high dimensionality and the standard statistical methods prove computationally intractable. This paper develops and addresses the theoretical convergence of a new high-dimensional Monte-Carlo approach called the localized ensemble Kalman smoother.

  4. Ensemble Methods Foundations and Algorithms

    CERN Document Server

    Zhou, Zhi-Hua

    2012-01-01

    An up-to-date, self-contained introduction to a state-of-the-art machine learning approach, Ensemble Methods: Foundations and Algorithms shows how these accurate methods are used in real-world tasks. It gives you the necessary groundwork to carry out further research in this evolving field. After presenting background and terminology, the book covers the main algorithms and theories, including Boosting, Bagging, Random Forest, averaging and voting schemes, the Stacking method, mixture of experts, and diversity measures. It also discusses multiclass extension, noise tolerance, error-ambiguity a

  5. Analysis of mesoscale forecasts using ensemble methods

    CERN Document Server

    Gross, Markus

    2016-01-01

    Mesoscale forecasts are now routinely performed as elements of operational forecasts and their outputs do appear convincing. However, despite their realistic appearance at times the comparison to observations is less favorable. At the grid scale these forecasts often do not compare well with observations. This is partly due to the chaotic system underlying the weather. Another key problem is that it is impossible to evaluate the risk of making decisions based on these forecasts because they do not provide a measure of confidence. Ensembles provide this information in the ensemble spread and quartiles. However, running global ensembles at the meso or sub mesoscale involves substantial computational resources. National centers do run such ensembles, but the subject of this publication is a method which requires significantly less computation. The ensemble enhanced mesoscale system presented here aims not at the creation of an improved mesoscale forecast model. Also it is not to create an improved ensemble syste...

  6. Measuring social interaction in music ensembles.

    Science.gov (United States)

    Volpe, Gualtiero; D'Ausilio, Alessandro; Badino, Leonardo; Camurri, Antonio; Fadiga, Luciano

    2016-05-01

    Music ensembles are an ideal test-bed for quantitative analysis of social interaction. Music is an inherently social activity, and music ensembles offer a broad variety of scenarios which are particularly suitable for investigation. Small ensembles, such as string quartets, are deemed a significant example of self-managed teams, where all musicians contribute equally to a task. In bigger ensembles, such as orchestras, the relationship between a leader (the conductor) and a group of followers (the musicians) clearly emerges. This paper presents an overview of recent research on social interaction in music ensembles with a particular focus on (i) studies from cognitive neuroscience; and (ii) studies adopting a computational approach for carrying out automatic quantitative analysis of ensemble music performances. PMID:27069054

  7. Interpreting Tree Ensembles with inTrees

    OpenAIRE

    Deng, Houtao

    2014-01-01

    Tree ensembles such as random forests and boosted trees are accurate but difficult to understand, debug and deploy. In this work, we provide the inTrees (interpretable trees) framework that extracts, measures, prunes and selects rules from a tree ensemble, and calculates frequent variable interactions. An rule-based learner, referred to as the simplified tree ensemble learner (STEL), can also be formed and used for future prediction. The inTrees framework can applied to both classification an...

  8. A Gaussian mixture ensemble transform filter

    OpenAIRE

    Reich, Sebastian

    2011-01-01

    We generalize the popular ensemble Kalman filter to an ensemble transform filter where the prior distribution can take the form of a Gaussian mixture or a Gaussian kernel density estimator. The design of the filter is based on a continuous formulation of the Bayesian filter analysis step. We call the new filter algorithm the ensemble Gaussian mixture filter (EGMF). The EGMF is implemented for three simple test problems (Brownian dynamics in one dimension, Langevin dynamics in two dimensions, ...

  9. Faire territoire au quotidien dans les grands ensembles HLM

    Directory of Open Access Journals (Sweden)

    Denis la Mache

    2012-05-01

    Full Text Available Cet article propose une lecture anthropologique de la manière dont les habitants des grands ensembles de périphéries urbaines délimitent, administrent, transforment matériellement et symboliquement les espaces et les lieux de leur quotidien pour faire territoire. Nous nous intéresserons à la fabrication de ces entités spatiales dont chaque individu se donne la liberté de disposer chaque jour selon un usage singulier et qu’il entoure d’un champ symbolique spécifique, garant d’identité. Ces « fabrications sociospatiales » seront abordées à partir d’une recherche empirique menée auprès d’habitants de deux terrains d’enquêtes situés dans des périphéries de villes moyennes.This paper proposes an anthropological reading of how the inhabitants of large urban peripheries define, administer, and process their daily spaces and places from a material as much as symbolical point of view to give sense to their territory. We will focus on the making of these spatial entities, witch everyone can dispose of everyday individually, to guarantee their identity. These “socio spatial creations” will be based on an empirical research, that is to say surveys conducted among the suburbians of two towns.

  10. Visualizing ensembles in structural biology.

    Science.gov (United States)

    Melvin, Ryan L; Salsbury, Freddie R

    2016-06-01

    Displaying a single representative conformation of a biopolymer rather than an ensemble of states mistakenly conveys a static nature rather than the actual dynamic personality of biopolymers. However, there are few apparent options due to the fixed nature of print media. Here we suggest a standardized methodology for visually indicating the distribution width, standard deviation and uncertainty of ensembles of states with little loss of the visual simplicity of displaying a single representative conformation. Of particular note is that the visualization method employed clearly distinguishes between isotropic and anisotropic motion of polymer subunits. We also apply this method to ligand binding, suggesting a way to indicate the expected error in many high throughput docking programs when visualizing the structural spread of the output. We provide several examples in the context of nucleic acids and proteins with particular insights gained via this method. Such examples include investigating a therapeutic polymer of FdUMP (5-fluoro-2-deoxyuridine-5-O-monophosphate) - a topoisomerase-1 (Top1), apoptosis-inducing poison - and nucleotide-binding proteins responsible for ATP hydrolysis from Bacillus subtilis. We also discuss how these methods can be extended to any macromolecular data set with an underlying distribution, including experimental data such as NMR structures. PMID:27179343

  11. Hierarchical Bayes Ensemble Kalman Filtering

    CERN Document Server

    Tsyrulnikov, Michael

    2015-01-01

    Ensemble Kalman filtering (EnKF), when applied to high-dimensional systems, suffers from an inevitably small affordable ensemble size, which results in poor estimates of the background error covariance matrix ${\\bf B}$. The common remedy is a kind of regularization, usually an ad-hoc spatial covariance localization (tapering) combined with artificial covariance inflation. Instead of using an ad-hoc regularization, we adopt the idea by Myrseth and Omre (2010) and explicitly admit that the ${\\bf B}$ matrix is unknown and random and estimate it along with the state (${\\bf x}$) in an optimal hierarchical Bayes analysis scheme. We separate forecast errors into predictability errors (i.e. forecast errors due to uncertainties in the initial data) and model errors (forecast errors due to imperfections in the forecast model) and include the two respective components ${\\bf P}$ and ${\\bf Q}$ of the ${\\bf B}$ matrix into the extended control vector $({\\bf x},{\\bf P},{\\bf Q})$. Similarly, we break the traditional backgrou...

  12. Visualizing ensembles in structural biology.

    Science.gov (United States)

    Melvin, Ryan L; Salsbury, Freddie R

    2016-06-01

    Displaying a single representative conformation of a biopolymer rather than an ensemble of states mistakenly conveys a static nature rather than the actual dynamic personality of biopolymers. However, there are few apparent options due to the fixed nature of print media. Here we suggest a standardized methodology for visually indicating the distribution width, standard deviation and uncertainty of ensembles of states with little loss of the visual simplicity of displaying a single representative conformation. Of particular note is that the visualization method employed clearly distinguishes between isotropic and anisotropic motion of polymer subunits. We also apply this method to ligand binding, suggesting a way to indicate the expected error in many high throughput docking programs when visualizing the structural spread of the output. We provide several examples in the context of nucleic acids and proteins with particular insights gained via this method. Such examples include investigating a therapeutic polymer of FdUMP (5-fluoro-2-deoxyuridine-5-O-monophosphate) - a topoisomerase-1 (Top1), apoptosis-inducing poison - and nucleotide-binding proteins responsible for ATP hydrolysis from Bacillus subtilis. We also discuss how these methods can be extended to any macromolecular data set with an underlying distribution, including experimental data such as NMR structures.

  13. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work by...

  14. Employment certificates on HRT

    CERN Multimedia

    HR Department

    2008-01-01

    As part of the ongoing drive to simplify and streamline administrative procedures and processes, the IT and HR Departments have made employment certificates available on a self-service basis on the HRT application, in the main menu under "My self services". All members of the personnel can thus obtain a certificate of employment or association, in French or in English, for the present or past contractual period. The HR Department’s Records Office remains responsible for issuing any special certificates that might be required. IT-AIS (Administrative Information Services) HR-SPS (Services, Procedures & Social) Records Office – Tel. 73700

  15. Joys of Community Ensemble Playing: The Case of the Happy Roll Elastic Ensemble in Taiwan

    Science.gov (United States)

    Hsieh, Yuan-Mei; Kao, Kai-Chi

    2012-01-01

    The Happy Roll Elastic Ensemble (HREE) is a community music ensemble supported by Tainan Culture Centre in Taiwan. With enjoyment and friendship as its primary goals, it aims to facilitate the joys of ensemble playing and the spirit of social networking. This article highlights the key aspects of HREE's development in its first two years…

  16. Digital signature and certification authorities

    OpenAIRE

    Prouza, Marek

    2013-01-01

    This bachelor thesis deal with Public Key Infrastructure issue, certificates and certification authorities. At the beginning there is included chapter about cryptography for better understanding including historical evolution of ciphers and analysis of three important ciphers. In the next chapter are discussed possibilities and principles of certification authorities, certificates and x509 standard. Following chapter discuss practical use of certificates in business, MS Office aplications and...

  17. 3 minutes pour développer son intelligence émotionnelle: journal filmé avec une classe d'enfants porteurs d'un handicap physique

    OpenAIRE

    Kozma, Kim; Savoy, Bernard

    2015-01-01

    Comment faire entrer le bonheur, le bien-être et le plaisir d’être ensemble dans ma classe d’enseignement spécialisé avec des enfants porteurs d’un handicap physique ? A la recherche d’une approche différente qui valorise l’humain plutôt que ses performances, je me suis intéressée à une autre forme d’intelligence. Le bonheur est aujourd’hui un sujet qui fascine le grand public et les scientifiques. Que de méthodes pour trouver son équilibre ! Une seule constance : cet équilibre passe par l’ac...

  18. Indirect Air Carrier Certification

    Data.gov (United States)

    Department of Homeland Security — Required information is entered in order to obtain an IAC certification and do business as an IAC. Information is verified through site inspections and inspections...

  19. Wind power certificate marketing

    International Nuclear Information System (INIS)

    Wind Power Certificate marketing is a green power development program in Canada. The Pembina Institute partnered with Vision Quest Windelectric in October 2003 to sell Wind Power Certificates to individuals and businesses. Individuals who buy Wind Power Certificates directly support the development of wind energy in Canada and support one of Pembina's main areas of work, the development of sustainable energy. This presentation outlined both the successes and challenges of marketing the certificates. Wind Power Certificates represent the benefits that wind power generation provides, such as zero emissions of greenhouse gases and regional air pollutants; minimal impacts on the biosphere; and, offsetting life-cycle impacts of other energy sources such as fossil fuels. They also represent quality assurance on new wind power commissioned after April 2001. In the price structure of Pembina's Wind Power Certificate, a premium of 2.7 cents per kWh is charged above the regular electricity price. The premium is lowered slightly for purchases of 200 MWh or more. Pembina also began a secondary campaign in July 2004 to have 20,000 computers powered by wind across Canada. This PC campaign offers the general public an option to support wind power development in a way that is easy to understand. In the PC campaign, a consumer is asked to pay $16 per 3 years for a laptop computer or $32 per 3 years for an average desktop computer. Vision Quest has received a Market Incentive Program grant through Natural Resources Canada to help market Pembina's wind power programs. Although the programs are too new to provide important statistical information, some small successes have been reported to date including 1950 MWh of Wind Power Certificates that have been purchased, representing a reduction of about 1730 tonnes of carbon dioxide. One of the challenges facing the Wind Power Certificate program is that some companies feel they already pay too much for electricity and the premium cost of

  20. Layered Ensemble Architecture for Time Series Forecasting.

    Science.gov (United States)

    Rahman, Md Mustafizur; Islam, Md Monirul; Murase, Kazuyuki; Yao, Xin

    2016-01-01

    Time series forecasting (TSF) has been widely used in many application areas such as science, engineering, and finance. The phenomena generating time series are usually unknown and information available for forecasting is only limited to the past values of the series. It is, therefore, necessary to use an appropriate number of past values, termed lag, for forecasting. This paper proposes a layered ensemble architecture (LEA) for TSF problems. Our LEA consists of two layers, each of which uses an ensemble of multilayer perceptron (MLP) networks. While the first ensemble layer tries to find an appropriate lag, the second ensemble layer employs the obtained lag for forecasting. Unlike most previous work on TSF, the proposed architecture considers both accuracy and diversity of the individual networks in constructing an ensemble. LEA trains different networks in the ensemble by using different training sets with an aim of maintaining diversity among the networks. However, it uses the appropriate lag and combines the best trained networks to construct the ensemble. This indicates LEAs emphasis on accuracy of the networks. The proposed architecture has been tested extensively on time series data of neural network (NN)3 and NN5 competitions. It has also been tested on several standard benchmark time series data. In terms of forecasting accuracy, our experimental results have revealed clearly that LEA is better than other ensemble and nonensemble methods. PMID:25751882

  1. Pour une démocratie socio-environnementale : cadre pour une plate-forme participative « transition écologique »

    OpenAIRE

    Clappe, Sylvie; Knipping, Solène; Rambaud, Léa; Badel, Catherine; Barth, Paul; Basset, Amandine; Bastianelli, Olivier; Benti, Benjamin; Berger, Caroline; Berger, Chloé; Bickerstaffe, Lily; Bonnin, Lucas; Bournhonesque, Raphael; Busi, Baptiste; Cardot, Victoire

    2014-01-01

    L’anthropocène triomphant actuel, avec ses forçages environnementaux et sociaux, est à l’origine de l’accélération des dégradations des milieux de vie sur Terre et de l’accentuation des tensions sociales et géopolitiques. Passer à un anthropocène de gestion équitable, informé et sobre vis-à-vis de toutes les ressources et dans tous les secteurs d’activité (slow anthropocene), impose une analyse préalable sur l’ensemble des activités et des rapports humains. Cette transition dite « écologique ...

  2. Rydberg ensemble based CNOTN gates using STIRAP

    Science.gov (United States)

    Gujarati, Tanvi; Duan, Luming

    2016-05-01

    Schemes for implementation of CNOT gates in atomic ensembles are important for realization of quantum computing. We present here a theoretical scheme of a CNOTN gate with an ensemble of three-level atoms in the lambda configuration and a single two-level control atom. We work in the regime of Rydberg blockade for the ensemble atoms due to excitation of the Rydberg control atom. It is shown that using STIRAP, atoms from one ground state of the ensemble can be adiabatically transferred to the other ground state, depending on the state of the control atom. A thorough analysis of adiabatic conditions for this scheme and the influence of the radiative decay is provided. We show that the CNOTN process is immune to the decay rate of the excited level in ensemble atoms. This work is supported by the ARL, the IARPA LogiQ program, and the AFOSR MURI program.

  3. Popular Ensemble Methods: An Empirical Study

    CERN Document Server

    Maclin, R; 10.1613/jair.614

    2011-01-01

    An ensemble consists of a set of individually trained classifiers (such as neural networks or decision trees) whose predictions are combined when classifying novel instances. Previous research has shown that an ensemble is often more accurate than any of the single classifiers in the ensemble. Bagging (Breiman, 1996c) and Boosting (Freund and Shapire, 1996; Shapire, 1990) are two relatively new but popular methods for producing ensembles. In this paper we evaluate these methods on 23 data sets using both neural networks and decision trees as our classification algorithm. Our results clearly indicate a number of conclusions. First, while Bagging is almost always more accurate than a single classifier, it is sometimes much less accurate than Boosting. On the other hand, Boosting can create ensembles that are less accurate than a single classifier -- especially when using neural networks. Analysis indicates that the performance of the Boosting methods is dependent on the characteristics of the data set being exa...

  4. Optimisation d’une installation solaire

    OpenAIRE

    CHEKKAF, Omar; GUENINECHE, Nabil

    2014-01-01

    Notre travail consiste à optimiser le fonctionnement d'une installation simple qui comprend un capteur solaire (bouilleur), une turbine à vapeur et un condenseur. Nous avons effectué des calculs pour différents débits de masse, à l'entrée du capteur solaire et différentes températures à l'entrée de la turbine. Nous avons trouvé que l'augmentation du débit massique et de la différence de température entre l'entrée et la sortie, conduit à une augmentation de la quantité de chaleur produite par ...

  5. Pour une Écologie des Somatiques?

    Directory of Open Access Journals (Sweden)

    Isabelle

    2014-12-01

    Full Text Available Ce texte traite de la parenté conceptuelle et théorique entre Somatiques et Écologie scientifique. Après une définition de la notion scientifique d’écologie, il s’attache à définir trois notions clés de l’écologie: celle de potentiel, qui permet de décrire de façon innovante le modèle de relation entre sujet et environnement au sein des Somatiques, et celles de diversité et de réciprocité, à partir desquelles l’article se veut une invitation et un programme à penser l’intégration des Somatiques au paradigme écologique scientifique, et en appelle aux acteurs somatiques pour transformer leurs pratiques selon une éthique environnementale.

  6. Proposition d'une étude stylistique de la céramique imprimée de Kobadi.

    OpenAIRE

    Gallin, Annabelle

    2002-01-01

    Nous proposons dans cet article une analyse complémentaire de la céramique de Kobadi en développant une étude stylistique. A cette fin, un protocole de description et d'analyse de la composition des décors est présenté. Il est appliqué aux tessons de bord découverts dans les sondages G, H et I en 1995 qui permettent de reconstituer la forme et l'ensemble de la partie ornée des vases. Deux groupes de céramique définis grâce à leur différence de pâte sont classés par la forme de pots et de lèvr...

  7. Generation of scenarios from calibrated ensemble forecasts with a dynamic ensemble copula coupling approach

    CERN Document Server

    Bouallegue, Zied Ben; Theis, Susanne E; Pinson, Pierre

    2015-01-01

    Probabilistic forecasts in the form of ensemble of scenarios are required for complex decision making processes. Ensemble forecasting systems provide such products but the spatio-temporal structures of the forecast uncertainty is lost when statistical calibration of the ensemble forecasts is applied for each lead time and location independently. Non-parametric approaches allow the reconstruction of spatio-temporal joint probability distributions at a low computational cost.For example, the ensemble copula coupling (ECC) method consists in rebuilding the multivariate aspect of the forecast from the original ensemble forecasts. Based on the assumption of error stationarity, parametric methods aim to fully describe the forecast dependence structures. In this study, the concept of ECC is combined with past data statistics in order to account for the autocorrelation of the forecast error. The new approach which preserves the dynamical development of the ensemble members is called dynamic ensemble copula coupling (...

  8. ENCORE: Software for Quantitative Ensemble Comparison.

    Directory of Open Access Journals (Sweden)

    Matteo Tiberti

    2015-10-01

    Full Text Available There is increasing evidence that protein dynamics and conformational changes can play an important role in modulating biological function. As a result, experimental and computational methods are being developed, often synergistically, to study the dynamical heterogeneity of a protein or other macromolecules in solution. Thus, methods such as molecular dynamics simulations or ensemble refinement approaches have provided conformational ensembles that can be used to understand protein function and biophysics. These developments have in turn created a need for algorithms and software that can be used to compare structural ensembles in the same way as the root-mean-square-deviation is often used to compare static structures. Although a few such approaches have been proposed, these can be difficult to implement efficiently, hindering a broader applications and further developments. Here, we present an easily accessible software toolkit, called ENCORE, which can be used to compare conformational ensembles generated either from simulations alone or synergistically with experiments. ENCORE implements three previously described methods for ensemble comparison, that each can be used to quantify the similarity between conformational ensembles by estimating the overlap between the probability distributions that underlie them. We demonstrate the kinds of insights that can be obtained by providing examples of three typical use-cases: comparing ensembles generated with different molecular force fields, assessing convergence in molecular simulations, and calculating differences and similarities in structural ensembles refined with various sources of experimental data. We also demonstrate efficient computational scaling for typical analyses, and robustness against both the size and sampling of the ensembles. ENCORE is freely available and extendable, integrates with the established MDAnalysis software package, reads ensemble data in many common formats, and can

  9. Le nouchi: une langue en devenir?

    OpenAIRE

    Grah, Brice Lopez

    2014-01-01

    Le mémoire présente une langue locale de la Côte-d’Ivoire, le nouchi, dans sa nature, son système, son fonctionnement, et ses rapports avec les autres langues qui composent le paysage linguistique ivoirien ; ceci pour susciter une volonté politique quant à sa standardisation et à son officialisation. Les travaux de Louis-jean Calvet, qui s’intéressent aux fonctions et usages des langues, à l’aménagement et aux politiques linguistiques, motivent et orientent l’argumentaire dével...

  10. Etude des possibilités d'utilisation des modèles numériques de surface en vue de la gestion durable des ressources forestières : Application dans une concession forestière au Gabon

    OpenAIRE

    Handerek, Daphné

    2010-01-01

    La planification du tracé du réseau routier est une étape importante en exploitation forestière tropicale mais de nombreuses contraintes y sont associées en vue d’une gestion durable des ressources forestières. La FAO a notamment édité un code d’Exploitation à Faible Impact (EFI) reprenant un ensemble de normes dont l’une des principales est la limitation des pentes maximales des routes principales (12 %) et secondaires (30 %). Cependant, à l’heure actuelle, la mise en place des routes est un...

  11. ENVIRONMENTAL MANAGEMENT SYSTEMS CERTIFICATION

    Directory of Open Access Journals (Sweden)

    Aniko Miler-Virc

    2012-12-01

    Full Text Available ISO 14001 prescribes the requirements for a system, not environmental performance itself. Similarly, certification is of the management system itself, not environmental performance. An audit is not conducted to ascertain whether your flue gas emissions are less than X part per million nitrous oxide or that your wastewater effluent contains less that Y milligrams of bacteria per litre. Consequently, the procces of auditing the system for compliance to the standard entails checking to see that all of the necessary components of a functioning system are present and working properly.           A company can have a complete and fully functional EMS as prescribed by ISO 14001 without being certified. As certification can add to the time and expense of EMS development, it is important for you to establish, in advance, whether certification is of net benefit to you. Although most companies that develop an EMS do in fact certify, there are cases where certification does not add immediate value. Certification is not always beneficial to small and medium sized companies. Certification is not always necessary for companies with one or two large clients with environmental demands who are satisfied that you have a functional EMS (second-party declaration. Whatever decision you make, it is important to remember that just as a driver′s licence does not automatically make you a good driver, ISO 14001 certification does not automatically make your company environmentally benign or ensure that you will continually improve environmental performance. The system is only as good as the people who operate it.

  12. Temperature nocturne et photosynthese. II. Une chambre d'assimilation climatisee pour la mesure des echanges gazeux de plantes entieres

    OpenAIRE

    Longuenesse, Jean Jacques; Conus, G.; Sarrouy, C

    1982-01-01

    Pour l’étude des arrière-effets de la température nocturne, on a mis au point un ensemble de deux chambres d’assimilation climatisées, avec régulation indépendante des conditions diurnes et nocturnes, séparément pour la partie aérienne et les racines. Ces chambres permettent de suivre pendant plusieurs jours les échanges gazeux de la partie aérienne et, éventuellement, des racines de plantes entières ayant une hauteur maximum de 1 m.

  13. Hybrid Data Assimilation without Ensemble Filtering

    Science.gov (United States)

    Todling, Ricardo; Akkraoui, Amal El

    2014-01-01

    The Global Modeling and Assimilation Office is preparing to upgrade its three-dimensional variational system to a hybrid approach in which the ensemble is generated using a square-root ensemble Kalman filter (EnKF) and the variational problem is solved using the Grid-point Statistical Interpolation system. As in most EnKF applications, we found it necessary to employ a combination of multiplicative and additive inflations, to compensate for sampling and modeling errors, respectively and, to maintain the small-member ensemble solution close to the variational solution; we also found it necessary to re-center the members of the ensemble about the variational analysis. During tuning of the filter we have found re-centering and additive inflation to play a considerably larger role than expected, particularly in a dual-resolution context when the variational analysis is ran at larger resolution than the ensemble. This led us to consider a hybrid strategy in which the members of the ensemble are generated by simply converting the variational analysis to the resolution of the ensemble and applying additive inflation, thus bypassing the EnKF. Comparisons of this, so-called, filter-free hybrid procedure with an EnKF-based hybrid procedure and a control non-hybrid, traditional, scheme show both hybrid strategies to provide equally significant improvement over the control; more interestingly, the filter-free procedure was found to give qualitatively similar results to the EnKF-based procedure.

  14. Nonequilibrium representative ensembles for isolated quantum systems

    International Nuclear Information System (INIS)

    An isolated quantum system is considered, prepared in a nonequilibrium initial state. In order to uniquely define the system dynamics, one has to construct a representative statistical ensemble. From the principle of least action it follows that the role of the evolution generator is played by a grand Hamiltonian, but not merely by its energy part. A theorem is proved expressing the commutators of field operators with operator products through variational derivatives of these products. A consequence of this theorem is the equivalence of the variational equations for field operators with the Heisenberg equations for the latter. A finite quantum system cannot equilibrate in the strict sense. But it can tend to a quasi-stationary state characterized by ergodic averages and the appropriate representative ensemble depending on initial conditions. Microcanonical ensemble, arising in the eigenstate thermalization, is just a particular case of representative ensembles. Quasi-stationary representative ensembles are defined by the principle of minimal information. The latter also implies the minimization of an effective thermodynamic potential. -- Highlights: → The evolution of a nonequilibrium isolated quantum system is considered. → The grand Hamiltonian is shown to be the evolution generator. → A theorem is proved connecting operator commutators with variational derivatives. → Quasi-stationary states are described by representative ensembles. → These ensembles, generally, depend on initial conditions.

  15. MSEBAG: a dynamic classifier ensemble generation based on `minimum-sufficient ensemble' and bagging

    Science.gov (United States)

    Chen, Lei; Kamel, Mohamed S.

    2016-01-01

    In this paper, we propose a dynamic classifier system, MSEBAG, which is characterised by searching for the 'minimum-sufficient ensemble' and bagging at the ensemble level. It adopts an 'over-generation and selection' strategy and aims to achieve a good bias-variance trade-off. In the training phase, MSEBAG first searches for the 'minimum-sufficient ensemble', which maximises the in-sample fitness with the minimal number of base classifiers. Then, starting from the 'minimum-sufficient ensemble', a backward stepwise algorithm is employed to generate a collection of ensembles. The objective is to create a collection of ensembles with a descending fitness on the data, as well as a descending complexity in the structure. MSEBAG dynamically selects the ensembles from the collection for the decision aggregation. The extended adaptive aggregation (EAA) approach, a bagging-style algorithm performed at the ensemble level, is employed for this task. EAA searches for the competent ensembles using a score function, which takes into consideration both the in-sample fitness and the confidence of the statistical inference, and averages the decisions of the selected ensembles to label the test pattern. The experimental results show that the proposed MSEBAG outperforms the benchmarks on average.

  16. Une-Mati lood vene keeles

    Index Scriptorium Estoniae

    2004-01-01

    Dagmar Normeti lasteraamatu "Une-Mati, Päris-Mati ja Tups" tõlget vene keelde (tõlkijad Irina Belobrovtseva ja Vitali Belobrovtsev; ill. Siima Shkop) esitletakse täna Kirjanike Liidu saalis; vt. ka Postimees, 19. märts, lk. 14

  17. La grammaire est une chanson douce

    Institute of Scientific and Technical Information of China (English)

    施婉丽

    2004-01-01

    Jeanne et Thomas, deux enfants rescapés d'un naufrage, échouent sur une ile paradisiaque. Or ils ne sont pas tout à fait sains et saufs puisqu'ils sont devenus muets. Plus aucun mot ne passe le seuil de leurs bouches. Le verbe les a désertées.

  18. Derivation of Mayer Series from Canonical Ensemble

    Science.gov (United States)

    Wang, Xian-Zhi

    2016-02-01

    Mayer derived the Mayer series from both the canonical ensemble and the grand canonical ensemble by use of the cluster expansion method. In 2002, we conjectured a recursion formula of the canonical partition function of a fluid (X.Z. Wang, Phys. Rev. E 66 (2002) 056102). In this paper we give a proof for this formula by developing an appropriate expansion of the integrand of the canonical partition function. We further derive the Mayer series solely from the canonical ensemble by use of this recursion formula.

  19. Ensemble Dynamics and Bred Vectors

    CERN Document Server

    Balci, Nusret; Restrepo, Juan M; Sell, George R

    2011-01-01

    We introduce the new concept of an EBV to assess the sensitivity of model outputs to changes in initial conditions for weather forecasting. The new algorithm, which we call the "Ensemble Bred Vector" or EBV, is based on collective dynamics in essential ways. By construction, the EBV algorithm produces one or more dominant vectors. We investigate the performance of EBV, comparing it to the BV algorithm as well as the finite-time Lyapunov Vectors. We give a theoretical justification to the observed fact that the vectors produced by BV, EBV, and the finite-time Lyapunov vectors are similar for small amplitudes. Numerical comparisons of BV and EBV for the 3-equation Lorenz model and for a forced, dissipative partial differential equation of Cahn-Hilliard type that arises in modeling the thermohaline circulation, demonstrate that the EBV yields a size-ordered description of the perturbation field, and is more robust than the BV in the higher nonlinear regime. The EBV yields insight into the fractal structure of th...

  20. Cooperative effects of neuronal ensembles.

    Science.gov (United States)

    Rose, G; Siebler, M

    1995-01-01

    Electrophysiological properties of neurons as the basic cellular elements of the central nervous system and their synaptic connections are well characterized down to a molecular level. However, the behavior of complex noisy networks formed by these constituents usually cannot simply be derived from the knowledge of its microscopic parameters. As a consequence, cooperative phenomena based on the interaction of neurons were postulated. This is a report on a study of global network spike activity as a function of synaptic interaction. We performed experiments in dissociated cultured hippocampal neurons and, for comparison, simulations of a mathematical model closely related to electrophysiology. Numeric analyses revealed that at a critical level of synaptic connectivity the firing behavior undergoes a phase transition. This cooperative effect depends crucially on the interaction of numerous cells and cannot be attributed to the spike threshold of individual neurons. In the experiment a drastic increase in the firing level was observed upon increase of synaptic efficacy by lowering of the extracellular magnesium concentration, which is compatible with our theoretical predictions. This "on-off" phenomenon demonstrates that even in small neuronal ensembles collective behavior can emerge which is not explained by the characteristics of single neurons. PMID:8542966

  1. Rehabilitation Counselor Certification: Moving Forward

    Science.gov (United States)

    Saunders, Jodi L.; Barros-Bailey, Mary; Chapman, Cindy; Nunez, Patricia

    2009-01-01

    This article provides a brief history of the Commission on Rehabilitation Counselor Certification and presents recent changes and strategic goals for moving forward. Challenges and opportunities for the profession in relation to certification are also discussed. (Contains 3 tables.)

  2. Vers une vision surnaturelle de la folie

    Directory of Open Access Journals (Sweden)

    Mabel Franzone

    2006-12-01

    Full Text Available A partir de la difficile notion de "folie", il s’agit d’aller vers l’exclusion dont cette maladie a fait l’objet dans le système occidental moderne. Un autre traitement de la maladie mentale se fait jour avec des penseurs contemporains, la résurgence d’autres cosmovisions et de philosophies anciennes. Ainsi les délires mystique, paranoïaque, schizophrénique peuvent être étudiés d’une part comme des ruptures de limites, d’autre part comme une mise en relation du corps avec l’esprit. Entre les deux, le langage fait oeuvre de trait d’union, langage qui, chez les malades, dénote une créativité, la poésie. Si cette poésie permet une sortie, une explosion des limites de la réalité vers des régions inconnues, peut-être peut-on voir la folie comme un déséquilibre par rapport au monde, au cosmos même, déséquilibre qui peut être traité en responsabilisant l’homme, en le pensant, en le mettant en question. De ce point de vue, la folie ressort comme quelque chose de positif, comme l’un des thèmes qui nous repositionnera face au monde, en mettant à notre portée d’autres ontologies.

  3. Soy production and certification

    DEFF Research Database (Denmark)

    Tomei, Julia; Semino, Stella Maris; Paul, Helena;

    2010-01-01

    With the rising emphasis on biofuels as a potential solution to climate change, this paper asks whether certification schemes, developed to promote sustainable feedstock production, are able to deliver genuine sustainability benefits. The Round Table on Responsible Soy (RTRS) is a certification...... scheme that aims to promote responsible soy production through the development of principles and criteria. However, can and does this initiative address the negative impacts associated with the intensive production of soy? Taking the example of soy biodiesel produced in Argentina, this paper asks whether...... the social and environmental impacts of soybean production can be mitigated by the RTRS. It concludes that at present certification schemes are unlikely to be able to address either the institutional challenges associated with their implementation or the detrimental impacts of the additional demand generated...

  4. Certification et equivalence

    Science.gov (United States)

    Colardyn, Danielle

    1992-11-01

    The new economic and social equilibrium which is gradually coming about in Europe has significant consequences in terms of mobility, recognition of qualifications and certification. Specifically in the educational arena, questions are raised as to the social and vocational value of certificates, and the recognition of vocational skills. These skills are part of the wealth of the particular countries in the Community, and of each of the individuals who are now confronted by the enlarged economic and social space, in its varying forms. In this European context, what is examined here is more particularly the French situation, from the point of view of the evolution of the notion of certification and recognition of skills, and of policies both of qualification, and of initial and continuing training of the work force.

  5. A 4D-Ensemble-Variational System for Data Assimilation and Ensemble Initialization

    Science.gov (United States)

    Bowler, Neill; Clayton, Adam; Jardak, Mohamed; Lee, Eunjoo; Jermey, Peter; Lorenc, Andrew; Piccolo, Chiara; Pring, Stephen; Wlasak, Marek; Barker, Dale; Inverarity, Gordon; Swinbank, Richard

    2016-04-01

    The Met Office has been developing a four-dimensional ensemble variational (4DEnVar) data assimilation system over the past four years. The 4DEnVar system is intended both as data assimilation system in its own right and also an improved means of initializing the Met Office Global and Regional Ensemble Prediction System (MOGREPS). The global MOGREPS ensemble has been initialized by running an ensemble of 4DEnVars (En-4DEnVar). The scalability and maintainability of ensemble data assimilation methods make them increasingly attractive, and 4DEnVar may be adopted in the context of the Met Office's LFRic project to redevelop the technical infrastructure to enable its Unified Model (MetUM) to be run efficiently on massively parallel supercomputers. This presentation will report on the results of the 4DEnVar development project, including experiments that have been run using ensemble sizes of up to 200 members.

  6. L’Apocalypse : jalons pour une lecture existentielle

    OpenAIRE

    Rognon, Frédéric

    2015-01-01

    L’Apocalypse a reçu une multitude d’interprétations, dont les principales sont ici évoquées. Les points forts et les limites de chacune d’entre elles sont également exposés. Puis nous proposons une autre relecture, de type existentielle, inspirée de Søren Kierkegaard et de Jacques Ellul. L’Apocalypse apparaît alors comme une révélation d’existence, d’une grande puissance, et d’une actualité inégalée.

  7. Transition from Poisson to circular unitary ensemble

    Indian Academy of Sciences (India)

    Vinayak; Akhilesh Pandey

    2009-09-01

    Transitions to universality classes of random matrix ensembles have been useful in the study of weakly-broken symmetries in quantum chaotic systems. Transitions involving Poisson as the initial ensemble have been particularly interesting. The exact two-point correlation function was derived by one of the present authors for the Poisson to circular unitary ensemble (CUE) transition with uniform initial density. This is given in terms of a rescaled symmetry breaking parameter Λ. The same result was obtained for Poisson to Gaussian unitary ensemble (GUE) transition by Kunz and Shapiro, using the contour-integral method of Brezin and Hikami. We show that their method is applicable to Poisson to CUE transition with arbitrary initial density. Their method is also applicable to the more general ℓ CUE to CUE transition where CUE refers to the superposition of ℓ independent CUE spectra in arbitrary ratio.

  8. Data assimilation the ensemble Kalman filter

    CERN Document Server

    Evensen, Geir

    2006-01-01

    Covers data assimilation and inverse methods, including both traditional state estimation and parameter estimation. This text and reference focuses on various popular data assimilation methods, such as weak and strong constraint variational methods and ensemble filters and smoothers.

  9. Irreplaceability of Neuronal Ensembles after Memory Allocation

    Directory of Open Access Journals (Sweden)

    Naoki Matsuo

    2015-04-01

    Full Text Available Lesion studies suggest that an alternative system can compensate for damage to the primary region employed when animals acquire a memory. However, it is unclear whether functional compensation occurs at the cellular ensemble level. Here, we inhibited the activities of a specific subset of neurons activated during initial learning by utilizing a transgenic mouse that expresses tetanus toxin (TeNT under the control of the c-fos promoter. Notably, suppression interfered with relearning while sparing the ability to acquire and express fear memory for a distinct context. These results suggest that the activity of the initial ensemble is preferentially dedicated to the same learning and that it is not replaceable once it is allocated. Our results provide substantial insights into the machinery underlying how the brain allocates individual memories to discrete neuronal ensembles and how it ensures that repetitive learning strengthens memory by reactivating the same neuronal ensembles.

  10. Board Certification in Counseling Psychology

    Science.gov (United States)

    Crowley, Susan L.; Lichtenberg, James W.; Pollard, Jeffrey W.

    2012-01-01

    Although specialty board certification by the American Board of Professional Psychology (ABPP) has been a valued standard for decades, the vast majority of counseling psychologists do not pursue board certification in the specialty. The present article provides a brief history of board certification in general and some historical information about…

  11. Adjustment of solar testing laboratory of INTA to the European Standard UNE EN 12975; Adaptacion de laboratorio de ensayo de sistemas solares termicos del INTA a la norma Europea UNE EN 12975

    Energy Technology Data Exchange (ETDEWEB)

    Rengel, G. R.; Vargas, V. L.; Narbona, D. J.

    2004-07-01

    INTA Terrestrial Energies Systems Laboratory has been for the last 23 years, the only accredited center in Spain as official Laboratory of the Ministry of Industry for flat solar collector certification tests. More than 250 tests has been performance by INTA Standard (INTA 61 00 01) during this period. Due to the next application of the European Standard UNE-EN 12975 for those kind of tests, it is set as main objective the accreditation by ENAC of the laboratory in agreement with the mentioned standard. For this reason, this INTA Laboratory is suffering many modifications concerning management requirements (a Quality System development) as well as technical requirements (design of new facilities). (Author)

  12. Reversible Projective Measurement in Quantum Ensembles

    CERN Document Server

    Khitrin, Anatoly; Lee, Jae-Seung

    2010-01-01

    We present experimental NMR demonstration of a scheme of reversible projective measurement, which allows extracting information on outcomes and probabilities of a projective measurement in a non-destructive way, with a minimal net effect on the quantum state of an ensemble. The scheme uses reversible dynamics and weak measurement of the intermediate state. The experimental system is an ensemble of 133Cs (S = 7/2) nuclei in a liquid-crystalline matrix.

  13. Controlling balance in an ensemble Kalman filter

    OpenAIRE

    G. A. Gottwald

    2014-01-01

    We present a method to control unbalanced fast dynamics in an ensemble Kalman filter by introducing a weak constraint on the imbalance in a spatially sparse observational network. We show that the balance constraint produces significantly more balanced analyses than ensemble Kalman filters without balance constraints and than filters implementing incremental analysis updates (IAU). Furthermore, our filter with the weak constraint on imbalance produces good rms error statisti...

  14. Calibrating ensemble reliability whilst preserving spatial structure

    Directory of Open Access Journals (Sweden)

    Jonathan Flowerdew

    2014-03-01

    Full Text Available Ensemble forecasts aim to improve decision-making by predicting a set of possible outcomes. Ideally, these would provide probabilities which are both sharp and reliable. In practice, the models, data assimilation and ensemble perturbation systems are all imperfect, leading to deficiencies in the predicted probabilities. This paper presents an ensemble post-processing scheme which directly targets local reliability, calibrating both climatology and ensemble dispersion in one coherent operation. It makes minimal assumptions about the underlying statistical distributions, aiming to extract as much information as possible from the original dynamic forecasts and support statistically awkward variables such as precipitation. The output is a set of ensemble members preserving the spatial, temporal and inter-variable structure from the raw forecasts, which should be beneficial to downstream applications such as hydrological models. The calibration is tested on three leading 15-d ensemble systems, and their aggregation into a simple multimodel ensemble. Results are presented for 12 h, 1° scale over Europe for a range of surface variables, including precipitation. The scheme is very effective at removing unreliability from the raw forecasts, whilst generally preserving or improving statistical resolution. In most cases, these benefits extend to the rarest events at each location within the 2-yr verification period. The reliability and resolution are generally equivalent or superior to those achieved using a Local Quantile-Quantile Transform, an established calibration method which generalises bias correction. The value of preserving spatial structure is demonstrated by the fact that 3×3 averages derived from grid-scale precipitation calibration perform almost as well as direct calibration at 3×3 scale, and much better than a similar test neglecting the spatial relationships. Some remaining issues are discussed regarding the finite size of the output

  15. Ensemble methods for noise in classification problems

    OpenAIRE

    Verbaeten, Sofie; Van Assche, Anneleen

    2003-01-01

    Ensemble methods combine a set of classifiers to construct a new classifier that is (often) more accurate than any of its component classifiers. In this paper, we use ensemble methods to identify noisy training examples. More precisely, we consider the problem of mislabeled training examples in classification tasks, and address this problem by pre-processing the training set, i.e. by identifying and removing outliers from the training set. We study a number of filter techniques that are based...

  16. Arthropathie destructrice des epaules au cours d�une acromegalie

    Directory of Open Access Journals (Sweden)

    Nessrine Akasbi

    2011-10-01

    Full Text Available L�acromegalie est une maladie endocrinienne rare, en rapport avec une hypersecretion d�hormone de croissance. Elle a des consequences rhumatologiques: l�arthropathie peripherique, l�atteinte rachidienne et les syndromes canalaires. L�atteinte articulaire accompagne une acromegalie active, sa survenue apres un traitement radical et une remission complete est rare. Nous presentons le cas d�une patiente de 70 ans ayant un antecedent d�acromegalie sur adenome hypophysaire il y a 25 ans, traitee chirurgicalement et declaree en remission complete, a developpe une arthropathie destructrice des deux epaules. Le but de notre observation est de mettre le point sur la possibilite d�une atteinte articulaire au cours de l�acromegalie et de son retentissement fonctionnelle.

  17. Un nouveau mode d'approche du management. La demarche qualite vers la certification

    Directory of Open Access Journals (Sweden)

    Jean Réné MOREAU

    2000-01-01

    Full Text Available La certification du système qualité consiste à certifier l’ensemble de l’organisation, des procédures, des procédés utilisés et des moyens nécessaires pour produire et garantir l’obtention de prestations conformes aux exigences que l’on se fixe. La certification suppose des normes que l’on appelle ISO 9000 qui prennent en compte les remarques des utilisateurs et des retours d’expériences. Cette qualification se mesure jusqu’à la satisfaction du client.

  18. Towards a GME ensemble forecasting system: Ensemble initialization using the breeding technique

    Directory of Open Access Journals (Sweden)

    Jan D. Keller

    2008-12-01

    Full Text Available The quantitative forecast of precipitation requires a probabilistic background particularly with regard to forecast lead times of more than 3 days. As only ensemble simulations can provide useful information of the underlying probability density function, we built a new ensemble forecasting system (GME-EFS based on the GME model of the German Meteorological Service (DWD. For the generation of appropriate initial ensemble perturbations we chose the breeding technique developed by Toth and Kalnay (1993, 1997, which develops perturbations by estimating the regions of largest model error induced uncertainty. This method is applied and tested in the framework of quasi-operational forecasts for a three month period in 2007. The performance of the resulting ensemble forecasts are compared to the operational ensemble prediction systems ECMWF EPS and NCEP GFS by means of ensemble spread of free atmosphere parameters (geopotential and temperature and ensemble skill of precipitation forecasting. This comparison indicates that the GME ensemble forecasting system (GME-EFS provides reasonable forecasts with spread skill score comparable to that of the NCEP GFS. An analysis with the continuous ranked probability score exhibits a lack of resolution for the GME forecasts compared to the operational ensembles. However, with significant enhancements during the 3 month test period, the first results of our work with the GME-EFS indicate possibilities for further development as well as the potential for later operational usage.

  19. Meaning of temperature in different thermostatistical ensembles.

    Science.gov (United States)

    Hänggi, Peter; Hilbert, Stefan; Dunkel, Jörn

    2016-03-28

    Depending on the exact experimental conditions, the thermodynamic properties of physical systems can be related to one or more thermostatistical ensembles. Here, we survey the notion of thermodynamic temperature in different statistical ensembles, focusing in particular on subtleties that arise when ensembles become non-equivalent. The 'mother' of all ensembles, the microcanonical ensemble, uses entropy and internal energy (the most fundamental, dynamically conserved quantity) to derive temperature as a secondary thermodynamic variable. Over the past century, some confusion has been caused by the fact that several competing microcanonical entropy definitions are used in the literature, most commonly the volume and surface entropies introduced by Gibbs. It can be proved, however, that only the volume entropy satisfies exactly the traditional form of the laws of thermodynamics for a broad class of physical systems, including all standard classical Hamiltonian systems, regardless of their size. This mathematically rigorous fact implies that negative 'absolute' temperatures and Carnot efficiencies more than 1 are not achievable within a standard thermodynamical framework. As an important offspring of microcanonical thermostatistics, we shall briefly consider the canonical ensemble and comment on the validity of the Boltzmann weight factor. We conclude by addressing open mathematical problems that arise for systems with discrete energy spectra. PMID:26903095

  20. Conductor gestures influence evaluations of ensemble performance.

    Science.gov (United States)

    Morrison, Steven J; Price, Harry E; Smedley, Eric M; Meals, Cory D

    2014-01-01

    Previous research has found that listener evaluations of ensemble performances vary depending on the expressivity of the conductor's gestures, even when performances are otherwise identical. It was the purpose of the present study to test whether this effect of visual information was evident in the evaluation of specific aspects of ensemble performance: articulation and dynamics. We constructed a set of 32 music performances that combined auditory and visual information and were designed to feature a high degree of contrast along one of two target characteristics: articulation and dynamics. We paired each of four music excerpts recorded by a chamber ensemble in both a high- and low-contrast condition with video of four conductors demonstrating high- and low-contrast gesture specifically appropriate to either articulation or dynamics. Using one of two equivalent test forms, college music majors and non-majors (N = 285) viewed sixteen 30 s performances and evaluated the quality of the ensemble's articulation, dynamics, technique, and tempo along with overall expressivity. Results showed significantly higher evaluations for performances featuring high rather than low conducting expressivity regardless of the ensemble's performance quality. Evaluations for both articulation and dynamics were strongly and positively correlated with evaluations of overall ensemble expressivity. PMID:25104944

  1. Une histoire évolutive de l’habitat martiniquais

    Directory of Open Access Journals (Sweden)

    Christophe Denise

    2012-04-01

    Full Text Available Au cœur de l’habitat rural martiniquais se trouve la case. Elle s’inscrit dans un ensemble (case et dépendances qui fait appel à une gestion de l’espace. Son architecture est intimement liée au mode d’habiter et par là même aux rapports qu’entretient l’individu avec la société. Si au cours de son évolution, la case a connu bon nombre d’aménagements, les caractères essentiels de cet habitat ont été préservés. Face à la transformation qu'a connu le paysage rural martiniquais depuis le milieu du XXe siècle, elle reste un héritage culturel caractéristique du langage architectural créole, patrimoine historique des anciennes sociétés coloniales qu’il convient de protéger.In the heart of the rural settlement, there is the hut. It takes its place in a whole (hut and outbuildings which has recourse to a space management. Its architecture is linked to the mode of life and the individual’s relations with the society. If in its evolution the hut undergone many adjustments, its essential characteristics have been preserved. Facing the transformations of the rural settlement since the middle of the twentieth century, it stays a cultural legacy characteristic of architectural creole language, historical patrimony of the ex-colonial societies which should be protected.

  2. Découverte d'une tumeur grêlique suite à une occlusion intestinale aigue chez une femme enceinte: à propos d'un cas

    OpenAIRE

    Chouaib, Naoufal; Rafai, Mostafa; El Bouti, Anas; Belkouch, Ahmed; El bakkali, Hicham; Belyamani, Lahcen

    2015-01-01

    L'association d'un cancer digestif avec la grossesse est rare et concerne avant tout les cancers colorectaux, de l'estomac ainsi que ceux se révélant par une tumeur de Krukenberg. Le diagnostic est souvent tardif expliquant la fréquence élevée des stades avancés. Nous rapportons un cas d'une femme enceinte qui a présenté une occlusion intestinale aigue sur tumeur colique. Il s'agissait d'une patiente enceinte de 32 semaines d'aménorrhées, admise pour syndrome occlusif évoluant depuis trois jo...

  3. La linguistique de corpus : une alternative [version abrégée

    OpenAIRE

    Teubert, Wolfgang

    2012-01-01

    La linguistique de corpus a été développé pour extraire d’un corpus les connaissances linguistiques nécessaires à l’enseignement des langues ; un corpus étant un ensemble collecté et ordonné de données langagières réelles. Faisant partie de la linguistique appliquée, la linguistique de corpus n’a jamais revendiqué réellement de cadre théorique propre. Cependant, elle a procuré une manière nouvelle de regarder le langage. La linguistique de corpus situe la signification dans le discours, dans ...

  4. Pharmacist specialty certification.

    Science.gov (United States)

    Durfee, Sharon M

    2012-03-01

    Nutrition support is a pharmacy specialty in which pharmacists work with prescribers, conduct order review, and either perform or oversee compounding of these complex parenteral nutrition formulations. Pharmacists should be certified in this specialty, and the options for certification are outlined in this article. PMID:22275326

  5. Ensemble postprocessing for probabilistic quantitative precipitation forecasts

    Science.gov (United States)

    Bentzien, S.; Friederichs, P.

    2012-12-01

    Precipitation is one of the most difficult weather variables to predict in hydrometeorological applications. In order to assess the uncertainty inherent in deterministic numerical weather prediction (NWP), meteorological services around the globe develop ensemble prediction systems (EPS) based on high-resolution NWP systems. With non-hydrostatic model dynamics and without parameterization of deep moist convection, high-resolution NWP models are able to describe convective processes in more detail and provide more realistic mesoscale structures. However, precipitation forecasts are still affected by displacement errors, systematic biases and fast error growth on small scales. Probabilistic guidance can be achieved from an ensemble setup which accounts for model error and uncertainty of initial and boundary conditions. The German Meteorological Service (Deutscher Wetterdienst, DWD) provides such an ensemble system based on the German-focused limited-area model COSMO-DE. With a horizontal grid-spacing of 2.8 km, COSMO-DE is the convection-permitting high-resolution part of the operational model chain at DWD. The COSMO-DE-EPS consists of 20 realizations of COSMO-DE, driven by initial and boundary conditions derived from 4 global models and 5 perturbations of model physics. Ensemble systems like COSMO-DE-EPS are often limited with respect to ensemble size due to the immense computational costs. As a consequence, they can be biased and exhibit insufficient ensemble spread, and probabilistic forecasts may be not well calibrated. In this study, probabilistic quantitative precipitation forecasts are derived from COSMO-DE-EPS and evaluated at more than 1000 rain gauges located all over Germany. COSMO-DE-EPS is a frequently updated ensemble system, initialized 8 times a day. We use the time-lagged approach to inexpensively increase ensemble spread, which results in more reliable forecasts especially for extreme precipitation events. Moreover, we will show that statistical

  6. A Unification of Ensemble Square Root Kalman Filters

    OpenAIRE

    Nerger, Lars; Janjic Pfander, Tijana; Schröter, Jens; Hiller, Wolfgang

    2012-01-01

    In recent years, several ensemble-based Kalman filter algorithms have been developed that have been classified as ensemble square-root Kalman filters. Parallel to this development, the SEIK (Singular ``Evolutive'' Interpolated Kalman) filter has been introduced and applied in several studies. Some publications note that the SEIK filter is an ensemble Kalman filter or even an ensemble square-root Kalman filter. This study examines the relation of the SEIK filter to ensemble square-root filters...

  7. On the Convergence of the Ensemble Kalman Filter

    OpenAIRE

    Mandel, Jan; Cobb, Loren; Beezley, Jonathan D.

    2009-01-01

    Convergence of the ensemble Kalman filter in the limit for large ensembles to the Kalman filter is proved. In each step of the filter, convergence of the ensemble sample covariance follows from a weak law of large numbers for exchangeable random variables, the continuous mapping theorem gives convergence in probability of the ensemble members, and $L^p$ bounds on the ensemble then give $L^p$ convergence.

  8. D'une industrie... l'autre?

    NARCIS (Netherlands)

    S. Musso; V.K. Nguyen

    2013-01-01

    À partir d’une contextualisation du texte de Cindy Patton, les auteur-e-s invitent à penser l’actualité des questions évoquées à l’aune d’enjeux contemporains relatifs à la production d’identités et de communautés que donnent à voir l’établissement des « cibles » de la prévention et du traitement du

  9. A multisite seasonal ensemble streamflow forecasting technique

    Science.gov (United States)

    Bracken, Cameron; Rajagopalan, Balaji; Prairie, James

    2010-03-01

    We present a technique for providing seasonal ensemble streamflow forecasts at several locations simultaneously on a river network. The framework is an integration of two recent approaches: the nonparametric multimodel ensemble forecast technique and the nonparametric space-time disaggregation technique. The four main components of the proposed framework are as follows: (1) an index gauge streamflow is constructed as the sum of flows at all the desired spatial locations; (2) potential predictors of the spring season (April-July) streamflow at this index gauge are identified from the large-scale ocean-atmosphere-land system, including snow water equivalent; (3) the multimodel ensemble forecast approach is used to generate the ensemble flow forecast at the index gauge; and (4) the ensembles are disaggregated using a nonparametric space-time disaggregation technique resulting in forecast ensembles at the desired locations and for all the months within the season. We demonstrate the utility of this technique in skillful forecast of spring seasonal streamflows at four locations in the Upper Colorado River Basin at different lead times. Where applicable, we compare the forecasts to the Colorado Basin River Forecast Center's Ensemble Streamflow Prediction (ESP) and the National Resource Conservation Service "coordinated" forecast, which is a combination of the ESP, Statistical Water Supply, a principal component regression technique, and modeler knowledge. We find that overall, the proposed method is equally skillful to existing operational models while tending to better predict wet years. The forecasts from this approach can be a valuable input for efficient planning and management of water resources in the basin.

  10. Hémangiome fusiforme: une localisation inhabituelle

    Science.gov (United States)

    Nasreddine, Fatima Zahra; Baghad, Bouchra; Chiheb, Soumiya

    2016-01-01

    L'hémangiome à cellules fusiformes été décrit par Weiss et Enzinger en 1986 et anciennement nommé hémangioendothéliome à cellules fusiformes. Depuis l'avènement des études immunohistochimique il n'est plus considéré en tant qu'angiosarcome de bas grade. C'est une tumeur bénigne vasculaire. Il touche presque exclusivement le derme des extrémités distales. Nous rapportons le premier cas avec localisation au niveau de l'omoplate, du sein, des cuisses et de la mandibule. Selon la littérature, seulement 9 cas localisés au niveau de la tête et le cou ont été rapportés. Nous rapportons un nouveau cas de cette entité rare et mal connue qui peut prêter confusion avec les tumeurs malignes. Notre patient avait une localisation au niveau de l'omoplate, du sein, des cuisses et de la mandibule. Une biopsie-exérèse était réalisée. L’évolution a été favorable avec un recul de 6 mois, sans rechute. PMID:27642429

  11. Individual differences in ensemble perception reveal multiple, independent levels of ensemble representation.

    Science.gov (United States)

    Haberman, Jason; Brady, Timothy F; Alvarez, George A

    2015-04-01

    Ensemble perception, including the ability to "see the average" from a group of items, operates in numerous feature domains (size, orientation, speed, facial expression, etc.). Although the ubiquity of ensemble representations is well established, the large-scale cognitive architecture of this process remains poorly defined. We address this using an individual differences approach. In a series of experiments, observers saw groups of objects and reported either a single item from the group or the average of the entire group. High-level ensemble representations (e.g., average facial expression) showed complete independence from low-level ensemble representations (e.g., average orientation). In contrast, low-level ensemble representations (e.g., orientation and color) were correlated with each other, but not with high-level ensemble representations (e.g., facial expression and person identity). These results suggest that there is not a single domain-general ensemble mechanism, and that the relationship among various ensemble representations depends on how proximal they are in representational space. PMID:25844624

  12. Generation of scenarios from calibrated ensemble forecasts with a dynamic ensemble copula coupling approach

    DEFF Research Database (Denmark)

    Ben Bouallègue, Zied; Heppelmann, Tobias; Theis, Susanne E.;

    2015-01-01

    Probabilistic forecasts in the form of ensemble of scenarios are required for complex decision making processes. Ensemble forecasting systems provide such products but the spatio-temporal structures of the forecast uncertainty is lost when statistical calibration of the ensemble forecasts...... is applied for each lead time and location independently. Non-parametric approaches allow the reconstruction of spatio-temporal joint probability distributions at a low computational cost.For example, the ensemble copula coupling (ECC) method consists in rebuilding the multivariate aspect of the forecast...... from the original ensemble forecasts. Based on the assumption of error stationarity, parametric methods aim to fully describe the forecast dependence structures. In this study, the concept of ECC is combined with past data statistics in order to account for the autocorrelation of the forecast error...

  13. Simulations in generalized ensembles through noninstantaneous switches

    Science.gov (United States)

    Giovannelli, Edoardo; Cardini, Gianni; Chelli, Riccardo

    2015-10-01

    Generalized-ensemble simulations, such as replica exchange and serial generalized-ensemble methods, are powerful simulation tools to enhance sampling of free energy landscapes in systems with high energy barriers. In these methods, sampling is enhanced through instantaneous transitions of replicas, i.e., copies of the system, between different ensembles characterized by some control parameter associated with thermodynamical variables (e.g., temperature or pressure) or collective mechanical variables (e.g., interatomic distances or torsional angles). An interesting evolution of these methodologies has been proposed by replacing the conventional instantaneous (trial) switches of replicas with noninstantaneous switches, realized by varying the control parameter in a finite time and accepting the final replica configuration with a Metropolis-like criterion based on the Crooks nonequilibrium work (CNW) theorem. Here we revise these techniques focusing on their correlation with the CNW theorem in the framework of Markovian processes. An outcome of this report is the derivation of the acceptance probability for noninstantaneous switches in serial generalized-ensemble simulations, where we show that explicit knowledge of the time dependence of the weight factors entering such simulations is not necessary. A generalized relationship of the CNW theorem is also provided in terms of the underlying equilibrium probability distribution at a fixed control parameter. Illustrative calculations on a toy model are performed with serial generalized-ensemble simulations, especially focusing on the different behavior of instantaneous and noninstantaneous replica transition schemes.

  14. Ensemble habitat mapping of invasive plant species

    Science.gov (United States)

    Stohlgren, T.J.; Ma, P.; Kumar, S.; Rocca, M.; Morisette, J.T.; Jarnevich, C.S.; Benson, N.

    2010-01-01

    Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. ?? 2010 Society for Risk Analysis.

  15. Écritures de soi en souffrance: une lecture des régimes structurant l’imaginaire du texte social vivant

    Directory of Open Access Journals (Sweden)

    Orazio Maria Valastro

    2010-02-01

    Full Text Available Les études ici réunies vont nous permettre d’examiner différentes genres d’écritures et typologies d’écrivains (poétique et épistolaire, roman autobiographique et autofiction, narratif et témoignage, explorant un corpus considérable (œuvres littéraires et littératures personnelles et des pratiques significatives (activités narratives et autobiographiques. Le thème proposé, les écritures de soi en souffrance, se dénoue sollicitant une réflexion sur les rapports entre les œuvres et les différents contextes sociaux et historiques. Nous pouvons envisager et saisir l’ensemble du corpus et des pratiques considérées en tant que texte social vivant, inscrivant l’expérience de l’existence et du monde dans la pratique de l’écriture. (... Nous allons solliciter et proposer une lecture sociologique et anthropologique de l’ensemble des études proposés au sein du numéro monographique, privilégiant une analyse de la matrice du discours social structurant la conscience individuelle et collective.

  16. Les Indications géographiques : une voie de pérennisation des processus d'action collective au sein des Systèmes agroalimentaires localisés ?

    OpenAIRE

    Fournier, Stéphane

    2008-01-01

    De l’analyse théorique croisée des dynamiques des processus locaux d’innovation et des processus de certification, il ressort que le couplage Système agroalimentaire localisé/Indication géographique (Syal/IG) peut permettre la pérennisation des dynamiques d’action collective. Les IG peuvent infléchir les relations de concurrence entre acteurs locaux grâce à l’ouverture de nouveaux marchés, et renforcer le processus de territorialisation grâce à une délimitation du territoire, une harmonisatio...

  17. Un ensemble urbain Art Déco en Egypte : Héliopolis, banlieue du Caire

    OpenAIRE

    Volait, Mercedes

    2006-01-01

    Analyse historique de l'ensemble urbain Art Déco d'Héliopolis, depuis la concession octroyée le 23 mai 1905 au baron Edouard Empain et à son associé Boghos Nubar pour la création d'une banlieue résidentielle au Caire. L'auteur montre que l'évolution urbaine et architecturale de la ville, fruit de brassages de populations et de cultures très diverses, a créé un mélange des genres cependant maîtrisé par la régulation esthétique tenace décidée dès l'origine par les promoteurs, qui s'est poursuiv...

  18. Modèle d'anisotropie des propriétés magnétiques induites par l'orientation préférentielle de forme dans une roche déformée

    OpenAIRE

    Vergne, R.; Mollard, P.; Vialon, P.; Rochette, P.

    1988-01-01

    Le but essentiel de ce travail est de montrer comment il est possible, à l'aide d'arguments simples : de justifier les corrélations observées entre l'anisotropie des propriétés magnétiques d'une roche et sa déformation interne et de les chiffrer dans le cas particulier de l'O.P.F. Pour modéliser une roche polyminérale, on considère l'ensemble des grains d'un même minéral : les marqueurs et le reste de la roche : la matrice. On applique à cet ensemble le modèle hydrodynamique en se bornant au ...

  19. Certification/enforcement analysis

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-01

    Industry compliance with minimum energy efficiency standards will be assured through a two-part program approach of certification and enforcement activities. The technical support document (TSD) presents the analyses upon which the proposed rule for assuring that consumer product comply with applicable energy efficiency standards is based. Much of the TSD is based upon support provided DOE by Vitro Laboratories. The OAO Corporation provided additional support in the development of the sampling plan incorporated in the proposed rule. Vitro's recommended approach to appliance certification and enforcement, developed after consideration of various program options, benefits, and impacts, establishes the C/E program framework, general criteria, and procedures for assuring a specified level of energy efficiency performance of covered consumer products. The results of the OAO analysis are given in Volume II of the TSD.

  20. "Comprehensive" energy certificate

    OpenAIRE

    Kolenac, Marko

    2013-01-01

    The thesis discusses calculated and measured energy certificates of a building, which were calculated and measured for the building of the Faculty of Civil Engineering and Geodesy in Ljubljana - the FGG building. The necessary calculations of the energy provided for functioning of the building were performed in accordance with the methodology specified in the applicable legal basis. The thesis provides measures for improving the thermal envelope of the building and presents an example of moni...

  1. Understanding Certificate Revocation

    OpenAIRE

    Hagström, Åsa

    2006-01-01

    Correct certificate revocation practices are essential to each public-key infrastructure. While there exist a number of protocols to achieve revocation in PKI systems, there has been very little work on the theory behind it: Which different types of revocation can be identified? What is the intended effect of a specific revocation type to the knowledge base of each entity? As a first step towards a methodology for the development of reliable models, we present a graph-based formalism for spec...

  2. Control and Synchronization of Neuron Ensembles

    CERN Document Server

    Li, Jr-Shin; Ruths, Justin

    2011-01-01

    Synchronization of oscillations is a phenomenon prevalent in natural, social, and engineering systems. Controlling synchronization of oscillating systems is motivated by a wide range of applications from neurological treatment of Parkinson's disease to the design of neurocomputers. In this article, we study the control of an ensemble of uncoupled neuron oscillators described by phase models. We examine controllability of such a neuron ensemble for various phase models and, furthermore, study the related optimal control problems. In particular, by employing Pontryagin's maximum principle, we analytically derive optimal controls for spiking single- and two-neuron systems, and analyze the applicability of the latter to an ensemble system. Finally, we present a robust computational method for optimal control of spiking neurons based on pseudospectral approximations. The methodology developed here is universal to the control of general nonlinear phase oscillators.

  3. Matrix averages relating to Ginibre ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, Peter J [Department of Mathematics and Statistics, University of Melbourne, Victoria 3010 (Australia); Rains, Eric M [Department of Mathematics, California Institute of Technology, Pasadena, CA 91125 (United States)], E-mail: p.forrester@ms.unimelb.edu.au

    2009-09-25

    The theory of zonal polynomials is used to compute the average of a Schur polynomial of argument AX, where A is a fixed matrix and X is from the real Ginibre ensemble. This generalizes a recent result of Sommers and Khoruzhenko (2009 J. Phys. A: Math. Theor. 42 222002), and furthermore allows analogous results to be obtained for the complex and real quaternion Ginibre ensembles. As applications, the positive integer moments of the general variance Ginibre ensembles are computed in terms of generalized hypergeometric functions; these are written in terms of averages over matrices of the same size as the moment to give duality formulas, and the averages of the power sums of the eigenvalues are expressed as finite sums of zonal polynomials.

  4. Clustering-based selective neural network ensemble

    Institute of Scientific and Technical Information of China (English)

    FU Qiang; HU Shang-xu; ZHAO Sheng-ying

    2005-01-01

    An effective ensemble should consist of a set of networks that are both accurate and diverse. We propose a novel clustering-based selective algorithm for constructing neural network ensemble, where clustering technology is used to classify trained networks according to similarity and optimally select the most accurate individual network from each cluster to make up the ensemble. Empirical studies on regression of four typical datasets showed that this approach yields significantly smaller en semble achieving better performance than other traditional ones such as Bagging and Boosting. The bias variance decomposition of the predictive error shows that the success of the proposed approach may lie in its properly tuning the bias/variance trade-offto reduce the prediction error (the sum of bias2 and variance).

  5. Luminescence simulations of ensembles of silicon nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood, Ross; Meldrum, Al [Department of Physics, University of Alberta, Edmonton (Canada)

    2009-05-15

    The luminescence of silicon nanocrystals (NCs) has attracted a great deal of interest due to the numerous potential photonic applications of light-emitting silicon. However, the excitation mechanisms and cluster-cluster interactions in densely-packed ensembles, as well as the recombination processes that influence the emission spectrum and lifetime are not yet well understood. In order to generate a more complete picture of the controlling parameters in the luminescence, a dynamic Monte Carlo model that incorporates several key physical processes for luminescent nanocrystal ensembles is developed. The model simulates Forster-type multipole energy transfer, tunnelling interactions, radiative decay and non-radiative trapping in physically realistic (lognormal) distributions of silicon NCs. The results of the simulation illustrate the effects of the NC size distribution, homogeneous and inhomogeneous broadening, NC packing density, and non-radiative trapping on the ensemble luminescence spectrum. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Embedded random matrix ensembles in quantum physics

    CERN Document Server

    Kota, V K B

    2014-01-01

    Although used with increasing frequency in many branches of physics, random matrix ensembles are not always sufficiently specific to account for important features of the physical system at hand. One refinement which retains the basic stochastic approach but allows for such features consists in the use of embedded ensembles.  The present text is an exhaustive introduction to and survey of this important field. Starting with an easy-to-read introduction to general random matrix theory, the text then develops the necessary concepts from the beginning, accompanying the reader to the frontiers of present-day research. With some notable exceptions, to date these ensembles have primarily been applied in nuclear spectroscopy. A characteristic example is the use of a random two-body interaction in the framework of the nuclear shell model. Yet, topics in atomic physics, mesoscopic physics, quantum information science and statistical mechanics of isolated finite quantum systems can also be addressed using these ensemb...

  7. Circular β ensembles, CMV representation, characteristic polynomials

    Institute of Scientific and Technical Information of China (English)

    SU ZhongGen

    2009-01-01

    In this note we first briefly review some recent progress in the study of the circular β ensemble on the unit circle, where 0 > 0 is a model parameter. In the special cases β = 1,2 and 4, this ensemble describes the joint probability density of eigenvalues of random orthogonal, unitary and sympletic matrices, respectively. For general β, Killip and Nenciu discovered a five-diagonal sparse matrix model, the CMV representation. This representation is new even in the case β = 2; and it has become a powerful tool for studying the circular β ensemble. We then give an elegant derivation for the moment identities of characteristic polynomials via the link with orthogonal polynomials on the unit circle.

  8. Ensemble Kalman methods for inverse problems

    International Nuclear Information System (INIS)

    The ensemble Kalman filter (EnKF) was introduced by Evensen in 1994 (Evensen 1994 J. Geophys. Res. 99 10143–62) as a novel method for data assimilation: state estimation for noisily observed time-dependent problems. Since that time it has had enormous impact in many application domains because of its robustness and ease of implementation, and numerical evidence of its accuracy. In this paper we propose the application of an iterative ensemble Kalman method for the solution of a wide class of inverse problems. In this context we show that the estimate of the unknown function that we obtain with the ensemble Kalman method lies in a subspace A spanned by the initial ensemble. Hence the resulting error may be bounded above by the error found from the best approximation in this subspace. We provide numerical experiments which compare the error incurred by the ensemble Kalman method for inverse problems with the error of the best approximation in A, and with variants on traditional least-squares approaches, restricted to the subspace A. In so doing we demonstrate that the ensemble Kalman method for inverse problems provides a derivative-free optimization method with comparable accuracy to that achieved by traditional least-squares approaches. Furthermore, we also demonstrate that the accuracy is of the same order of magnitude as that achieved by the best approximation. Three examples are used to demonstrate these assertions: inversion of a compact linear operator; inversion of piezometric head to determine hydraulic conductivity in a Darcy model of groundwater flow; and inversion of Eulerian velocity measurements at positive times to determine the initial condition in an incompressible fluid. (paper)

  9. Efficient inference of protein structural ensembles

    CERN Document Server

    Lane, Thomas J; Beauchamp, Kyle A; Pande, Vijay S

    2014-01-01

    It is becoming clear that traditional, single-structure models of proteins are insufficient for understanding their biological function. Here, we outline one method for inferring, from experiments, not only the most common structure a protein adopts (native state), but the entire ensemble of conformations the system can adopt. Such ensemble mod- els are necessary to understand intrinsically disordered proteins, enzyme catalysis, and signaling. We suggest that the most difficult aspect of generating such a model will be finding a small set of configurations to accurately model structural heterogeneity and present one way to overcome this challenge.

  10. SEIK - the unknown ensemble Kalman filter

    OpenAIRE

    Nerger, Lars; Janjic Pfander, Tijana; Hiller, Wolfgang; Schröter, Jens

    2009-01-01

    The SEIK filter (Singular "Evolutive" Interpolated Kalman filter) hasbeen introduced in 1998 by D.T. Pham as a variant of the SEEK filter,which is a reduced-rank approximation of the Extended KalmanFilter. In recent years, it has been shown that the SEIK filter isan ensemble-based Kalman filter that uses a factorization rather thansquare-root of the state error covariance matrix. Unfortunately, theexistence of the SEIK filter as an ensemble-based Kalman filter withsimilar efficiency as the la...

  11. Ensemble computing for the petroleum industry

    International Nuclear Information System (INIS)

    Computer downsizing is one of the most often used buzzwords in today's competitive business, and the petroleum industry is at the forefront of this revolution. Ensemble computing provides the key for computer downsizing with its first incarnation, i.e., workstation farms. This paper concerns the importance of increasing the productivity cycle and not just the execution time of a job. The authors introduce the concept of ensemble computing and workstation farms. The they discuss how different computing paradigms can be addressed by workstation farms

  12. Analyse des signaux électrocardiogrammes:Une approche fractale

    OpenAIRE

    SEDJELMACI, Ibticeme

    2009-01-01

    Notre travail consiste à traiter les signaux ECG de sujets de différents ages, normaux et présentant des pathologies par une nouvelle approche en traitement du signal appelée analyse fractale pour une identification de différentes pathologies et une éventuelle possibilité de trouver une signature fractale. L'utilisation d'ondelettes et d'outils d'analyse fractale est appropriée à l'analyse des signaux irréguliers. La caractérisation de la régularité (locale) est importante dans...

  13. Efficient Certificate Management in VANET

    OpenAIRE

    Samara, Ghassan

    2012-01-01

    Vehicular Ad hoc Networks is one of the most challenging research area in the field of Mobile Ad Hoc Networks, in this research We propose a flexible, simple, and scalable design for VANET certificates, and new methods for efficient certificate management, which will Reduce channel overhead by eliminating the use of CRL, and make Better certificate Revocation Management. Also it will increase the security of the network and helps in identifying the adversary vehicle.

  14. Total probabilities of ensemble runoff forecasts

    Science.gov (United States)

    Olav Skøien, Jon; Bogner, Konrad; Salamon, Peter; Smith, Paul; Pappenberger, Florian

    2016-04-01

    Ensemble forecasting has for a long time been used as a method in meteorological modelling to indicate the uncertainty of the forecasts. However, as the ensembles often exhibit both bias and dispersion errors, it is necessary to calibrate and post-process them. Two of the most common methods for this are Bayesian Model Averaging (Raftery et al., 2005) and Ensemble Model Output Statistics (EMOS) (Gneiting et al., 2005). There are also methods for regionalizing these methods (Berrocal et al., 2007) and for incorporating the correlation between lead times (Hemri et al., 2013). Engeland and Steinsland Engeland and Steinsland (2014) developed a framework which can estimate post-processing parameters which are different in space and time, but still can give a spatially and temporally consistent output. However, their method is computationally complex for our larger number of stations, and cannot directly be regionalized in the way we would like, so we suggest a different path below. The target of our work is to create a mean forecast with uncertainty bounds for a large number of locations in the framework of the European Flood Awareness System (EFAS - http://www.efas.eu) We are therefore more interested in improving the forecast skill for high-flows rather than the forecast skill of lower runoff levels. EFAS uses a combination of ensemble forecasts and deterministic forecasts from different forecasters to force a distributed hydrologic model and to compute runoff ensembles for each river pixel within the model domain. Instead of showing the mean and the variability of each forecast ensemble individually, we will now post-process all model outputs to find a total probability, the post-processed mean and uncertainty of all ensembles. The post-processing parameters are first calibrated for each calibration location, but assuring that they have some spatial correlation, by adding a spatial penalty in the calibration process. This can in some cases have a slight negative

  15. Evolution de la charge électrique d'une particule heurtant une paroi solide

    Science.gov (United States)

    Touchard, G.; Zerghouni, A.; Watanabe, S.; Borzeix, J.

    1991-07-01

    This study, essentially experimental, relates the electric charge generated by the shock of particles on a conducting wall (copper) and on an insulating one (polyethylene). The experiments are realised with an equipment connected to a data acquisition system. We have analysed the influence of differents parameters: impact angle; particle size; initial charge of the particles; impact velocity. Then from these experiments it is possible to point out the charging process of a particle for successive shocks. Le travail que nous présentons est une étude expérimentale du phénomène de génération de charges par collisions sur des surfaces métallique (cuivre) et isolante (polyéthylène). Les expériences sont réalisées sur un dispositif relié à un système d'acquisition de données. Nous avons procédé à l'étude de l'influence de plusieurs paramètres sur ce phénomène tels que : l'angle de choc ; les dimensions des particules ; la charge initiale des particules ; la vitesse au moment du choc. Nous avons aussi mis en évidence l'existence d'une charge de saturation qu'acquiert une particule après un grand nombre de chocs avec une paroi solide.

  16. Une hanche douloureuse révélatrice d'une histiocytose osseuse multifocale

    Science.gov (United States)

    Lahrach, Kamal; Alaoui, Adil; el Kadi, Khalid Ibn; Marzouki, Amine; Boutayeb, Fawzi

    2014-01-01

    L'histiocytose langerhansienne est une maladie rare qui touche principalement l'enfant et l'adulte jeune. Elle peut prendre plusieurs aspects, L'atteinte osseuse peut être uni- ou multifocale. Nous rapportons une observation d'histiocytose langerhansienne osseuse multifocale, révélée chez un patient âgé de 23 ans et ayant touché le col fémoral droit. La scintigraphie osseuse a permis de retrouver plusieurs localisations: l'os temporal, humérale et scapulaire droite. En raison du risque fracturaire, le patient a bénéficié d'une ostéosynthèse par vis-plaque DHS avec curetage biopsie de la lésion. L'examen histologique a révélé une histiocytose langerhansienne. L'évolution fut favorable après chimiothérapie par voie générale. PMID:25018840

  17. Sarcoidose et spondylarthrite ankylosante: une association rare

    Directory of Open Access Journals (Sweden)

    Fatima Zahra El Ouazzani

    2011-03-01

    Full Text Available L’association spondylarthrite ankylosante et sarcoïdose est rare, seize cas ont été publiés dans la littérature, nous en rapportons un nouveau cas. Cette association qui pose des problèmes diagnostiques est probablement fortuite du fait de l’absence de facteurs génétiques prédisposant partagés et du petit nombre des cas publiés, mais elle suggère l’hypothèse d’une liaison physiopathologique entre eux.

  18. Einstein une biographie dessinée

    CERN Document Server

    Maier, Corinne

    2015-01-01

    « Je m'appelle Albert Einstein. En voulant comprendre l'univers, j'ai libéré des forces de destruction terrifiantes. Mais il faut continuer à chercher le grand secret du cosmos. » Albert Einstein (1879-1955) est un immense génie devenu, sans le vouloir, une star de la science. Avec ses théories de la relativité restreinte puis de la relativité générale, il a radicalement transformé nos vies. Voici le récit de son existence passionnée et de ses contributions fondamentales.

  19. Une sociologie de la petite ville

    OpenAIRE

    Roques, Jean-Luc

    2012-01-01

    Le présent article se proposera au regard de travaux sociologiques et de deux séries d’études que nous avons menées de définir ce qu’est une petite ville. Les petites villes, dans le cas de la France, sont des communes ayant un nombre limité d’habitants. Mais elles ne sont pas que cela. Sous la pression de forces exogènes, elles tentent de maintenir inexorablement ce qui leur reste : leur culture locale. Elles mettent alors en exergue leur territoire et leur histoire par le biais de groupes s...

  20. Une ou plusieurs sociologies ?

    Directory of Open Access Journals (Sweden)

    Nathalie Heinich

    2012-01-01

    Full Text Available Après une ébauche de diagnostic des causes et des effets de la « bulle » sociologique qui s’est créée en France dans la dernière génération, cet article reprend une tentative de cartographie des quatre grandes tendances de la sociologie telle qu’elle avait été proposée il y a quelques années dans la Revue du Mauss. Il s’agit de mettre en évidence, par-delà l’apparente homogénéité de la discipline intitulée « sociologie », deux grandes lignes de clivage : d’une part, l’opposition entre une « sociologie du social » et une « sociologie de l’expérience » ; d’autre part, une sociologie à visée normative et une sociologie analytico-descriptive. Une fois croisées, ces lignes dessinent quatre zones (ou familles sociologiques, entre quatre « points cardinaux » (ou positions idéal-typiques dont elles s’approchent plus ou moins. L’article se termine par un court plaidoyer en faveur d’une sociologie de l’expérience analytico-descriptive, en tant qu’elle est la plus spécifique de ce qu’autorisent les méthodes et les outils de cette discipline.¿Una o varias sociologías? Esbozo « cartográfico »Después de realizar un bosquejo del diagnóstico de las causas y de los efectos de la « burbuja » sociológica que se formó en Francia en el transcurso de la generación anterior, este artículo retoma una tentativa de « cartografía » de las cuatro principales tendencias de la sociología tal como había sido representada hace varios años en la Revue du Mauss. Se trata de poner en evidencia, más allá de la homogeneidad aparente de la materia llamada « sociología », dos grandes líneas de fractura: por una parte la oposición entre una « sociología de lo social » y una « sociología de la experiencia ». Por otra parte una sociología con objetivos normativos y una sociología analítico-descriptiva. Una vez cruzadas esas líneas aparecen cuatro zonas (o familias

  1. Ensemble. Mobile Learning to Promote Social Inclusion

    OpenAIRE

    G. Bonaiuti; Ranieri, M.; P. Ravotto

    2010-01-01

    Final English Booklet of Ensemble project. Mobile learning, or m-learning, is the new term that is gaining ground in the educational technology vocabulary. The project has tried to find out how mobile devices could be integrated into learning settings to improve social inclusion.

  2. Canonical Ensemble Model for Black Hole Radiation

    Indian Academy of Sciences (India)

    Jingyi Zhang

    2014-09-01

    In this paper, a canonical ensemble model for the black hole quantum tunnelling radiation is introduced. In this model the probability distribution function corresponding to the emission shell is calculated to second order. The formula of pressure and internal energy of the thermal system is modified, and the fundamental equation of thermodynamics is also discussed.

  3. Semi-classical approximation and microcanonical ensemble

    International Nuclear Information System (INIS)

    For quantum mechanical systems with spherically symmetric potential the improved W.K.B. approximation of Elworthy and Truman corresponds to the classical microcanonical ensemble in the limit where (h/2π) goes to zero, at least for small time. (orig.)

  4. NYYD Ensemble ja Riho Sibul / Anneli Remme

    Index Scriptorium Estoniae

    Remme, Anneli, 1968-

    2001-01-01

    Gavin Bryarsi teos "Jesus' Blood Never Failed Me Yet" NYYD Ensemble'i ja Riho Sibula esituses 27. detsembril Pauluse kirikus Tartus ja 28. detsembril Rootsi- Mihkli kirikus Tallinnas. Kaastegevad Tartu Ülikooli Kammerkoor (Tartus) ja kammerkoor Voces Musicales (Tallinnas). Kunstiline juht Olari Elts

  5. Conductor gestures influence evaluations of ensemble performance

    Directory of Open Access Journals (Sweden)

    Steven eMorrison

    2014-07-01

    Full Text Available Previous research has found that listener evaluations of ensemble performances vary depending on the expressivity of the conductor’s gestures, even when performances are otherwise identical. It was the purpose of the present study to test whether this effect of visual information was evident in the evaluation of specific aspects of ensemble performance, articulation and dynamics. We constructed a set of 32 music performances that combined auditory and visual information and were designed to feature a high degree of contrast along one of two target characteristics: articulation and dynamics. We paired each of four music excerpts recorded by a chamber ensemble in both a high- and low-contrast condition with video of four conductors demonstrating high- and low-contrast gesture specifically appropriate to either articulation or dynamics. Using one of two equivalent test forms, college music majors and nonmajors (N = 285 viewed sixteen 30-second performances and evaluated the quality of the ensemble’s articulation, dynamics, technique and tempo along with overall expressivity. Results showed significantly higher evaluations for performances featuring high rather than low conducting expressivity regardless of the ensemble’s performance quality. Evaluations for both articulation and dynamics were strongly and positively correlated with evaluations of overall ensemble expressivity.

  6. AUC-Maximizing Ensembles through Metalearning.

    Science.gov (United States)

    LeDell, Erin; van der Laan, Mark J; Peterson, Maya

    2016-05-01

    Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree. PMID:27227721

  7. Partition Function of Interacting Calorons Ensemble

    CERN Document Server

    Deldar, Sedigheh

    2015-01-01

    We present a method for computing the partition function of a caloron ensemble taking into account the interaction of calorons. We focus on caloron-Dirac string interaction and show that the metric that Diakonov and Petrov offered works well in the limit where this interaction occurs. We suggest computing the correlation function of two polyakov loops by applying Ewald's method.

  8. Partition function of interacting calorons ensemble

    Science.gov (United States)

    Deldar, S.; Kiamari, M.

    2016-01-01

    We present a method for computing the partition function of a caloron ensemble taking into account the interaction of calorons. We focus on caloron-Dirac string interaction and show that the metric that Diakonov and Petrov offered, works well in the limit where this interaction occurs. We suggest computing the correlation function of two polyakov loops by applying Ewald's method.

  9. The Hydrologic Ensemble Prediction Experiment (HEPEX)

    Science.gov (United States)

    Wood, Andy; Wetterhall, Fredrik; Ramos, Maria-Helena

    2015-04-01

    The Hydrologic Ensemble Prediction Experiment was established in March, 2004, at a workshop hosted by the European Center for Medium Range Weather Forecasting (ECMWF), and co-sponsored by the US National Weather Service (NWS) and the European Commission (EC). The HEPEX goal was to bring the international hydrological and meteorological communities together to advance the understanding and adoption of hydrological ensemble forecasts for decision support. HEPEX pursues this goal through research efforts and practical implementations involving six core elements of a hydrologic ensemble prediction enterprise: input and pre-processing, ensemble techniques, data assimilation, post-processing, verification, and communication and use in decision making. HEPEX has grown through meetings that connect the user, forecast producer and research communities to exchange ideas, data and methods; the coordination of experiments to address specific challenges; and the formation of testbeds to facilitate shared experimentation. In the last decade, HEPEX has organized over a dozen international workshops, as well as sessions at scientific meetings (including AMS, AGU and EGU) and special issues of scientific journals where workshop results have been published. Through these interactions and an active online blog (www.hepex.org), HEPEX has built a strong and active community of nearly 400 researchers & practitioners around the world. This poster presents an overview of recent and planned HEPEX activities, highlighting case studies that exemplify the focus and objectives of HEPEX.

  10. Tiered Evaluation in Large Ensemble Settings.

    Science.gov (United States)

    Scott, David

    1998-01-01

    Discusses the use of a tiered evaluation system (TES) that allows students to work at different levels, enables teachers to assess progress objectively, and presents students with appropriate challenges in the music ensembles. Focuses on how TES works and its advantages, considers the challenges and flexibility of TES, and provides samples. (CMK)

  11. Toward Manipulating Quantum Information with Atomic Ensembles

    NARCIS (Netherlands)

    Lukin, M.D.; André, A.; Eisaman, M.D.; Hohensee, M.; Phillips, D.F.; Wal, C.H. van der; Walsworth, R.L.; Zibrov, A.S.

    2003-01-01

    We review several ideas for manipulation of quantum information using atomic ensembles and photons and describe some preliminary experiments toward their implementation. In particular, we review a technique that allows for robust transfer of quantum states between light fields and metastable states

  12. Lorentz-invariant ensembles of vector backgrounds

    International Nuclear Information System (INIS)

    We consider gauge field theories in the presence of ensembles of vector backgrounds. While Lorentz invariance is explicitly broken in the presence of any single background, here, the Lorentz invariance of the theory is restored by averaging over a Lorentz-invariant ensemble of backgrounds, i.e., a set of background vectors that is mapped onto itself under Lorentz transformations. This framework is used to study the effects of a non-trivial but Lorentz-invariant vacuum structure or mass dimension two vector condensates by identifying the background with a shift of the gauge field. Up to now, the ensembles used in the literature comprise configurations corresponding to non-zero field tensors together with such with vanishing field strength. We find that even when constraining the ensembles to pure gauge configurations, the usual high-energy degrees of freedom are removed from the spectrum of asymptotic states in the presence of said backgrounds in Euclidean and in Minkowski space. We establish this result not only for the propagators to all orders in the background and otherwise at tree level but for the full propagator

  13. Large Ensembles of Regional Climate Projections

    Science.gov (United States)

    Massey, Neil; Allen, Myles; Hall, Jim

    2016-04-01

    Projections of regional climate change have great utility for impact assessment at a local scale. The CORDEX climate projection framework presents a method of providing these regional projections by driving a regional climate model (RCM) with output from CMIP5 climate projection runs of global climate models (GCM). This produces an ensemble of regional climate projections, sampling the model uncertainty, the forcing uncertainty and the uncertainty of the response of the climate system to the increase in greenhouse gas (GHG) concentrations. Using the weather@home project to compute large ensembles of RCMs via volunteer distributed computing presents another method of generating projections of climate variables and also allows the sampling of the uncertainty due to internal variability. weather@home runs both a RCM and GCM on volunteer's home computers, with the free-running GCM driving the boundaries of the RCM. The GCM is an atmosphere only model and requires forcing at the lower boundary with sea-surface temperature (SST) and sea-ice concentration (SIC) data. By constructing SST and SIC projections, using projections of GHG and other atmospheric gases, and running the weather@home RCM and GCM with these forcings, large ensembles of projections of climate variables at regional scales can be made. To construct the SSTs and SICs, a statistical model is built to represent the response of SST and SIC to increases in GHG concentrations in the CMIP5 ensemble, for both the RCP4.5 and RCP8.5 scenarios. This statistical model uses empirical orthogonal functions (EOFs) to represent the change in the long term trend of SSTs in the CMIP5 projections. A multivariate distribution of the leading principle components (PC) is produced using a copula and sampled to produce a timeseries of PCs which are recombined with the EOFs to generate a timeseries of SSTs, with internal variability added from observations. Hence, a large ensemble of SST projections is generated, with each SST

  14. Une approche non linéaire pour la reconnaissance des formes statistique: application à la céphalométrie

    OpenAIRE

    Romaniuk, Barbara; Desvignes, Michel; Robiaille, Julien; Revenu, Marinette; Deshayes, Marie-Josèphe

    2002-01-01

    Dans cet article, nous comparons deux approches, l'une linéaire, l'autre non linéaire, pour la localisation statistique de points caractéristiques sur des images 2D. Un modèle statistique est construit à partir d'un ensemble d'images expertisées, nécessitant un recalage entre images. Le recalage rigide est la solution linéaire classique, que nous comparons à une solution non linéaire : elle consiste à projeter les coordonnées des points expertisés dans un espace de dimension supérieure et à r...

  15. Conception et réalisation d'une instrumentation terminale intégrée en chirurgie mini-invasive robotisée

    OpenAIRE

    Van Meer, Frédérick

    2005-01-01

    On assiste depuis quelques années à l'émergence d'une robotique médicale proposée pour accroître la précision des actes, améliorer les conditions de travail de l'équipe chirurgicale et le confort du patient. Nos recherches s'inscrivent dans le projet national EndoXiroB du RNTS dont l'objectif est la réalisation d'un ensemble robotisé de chirurgie mini-invasive. Elles sont dédiées à la conception et à la réalisation, en s'appuyant sur les technologies microsystèmes, d' une instrumentation chir...

  16. Space Applications for Ensemble Detection and Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ensemble Detection is both a measurement technique and analysis tool. Like a prism that separates light into spectral bands, an ensemble detector mixes a signal...

  17. Ensemble-based Kalman Filters in Strongly Nonlinear Dynamics

    Institute of Scientific and Technical Information of China (English)

    Zhaoxia PU; Joshua HACKER

    2009-01-01

    This study examines the effectiveness of ensemble Kalman filters in data assimilation with the strongly nonlinear dynamics of the Lorenz-63 model, and in particular their use in predicting the regime transition that occurs when the model jumps from one basin of attraction to the other. Four configurations of the ensemble-based Kalman filtering data assimilation techniques, including the ensemble Kalman filter, ensemble adjustment Kalman filter, ensemble square root filter and ensemble transform Kalman filter, are evaluated with their ability in predicting the regime transition (also called phase transition) and also are compared in terms of their sensitivity to both observational and sampling errors. The sensitivity of each ensemble-based filter to the size of the ensemble is also examined.

  18. Global Ensemble Forecast System (GEFS) [2.5 Deg.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Ensemble Forecast System (GEFS) is a weather forecast model made up of 21 separate forecasts, or ensemble members. The National Centers for Environmental...

  19. Evaluation of an ensemble-based incremental variational data assimilation

    OpenAIRE

    Yang, Yin; Robinson, Cordelia; Heitz, Dominique; Mémin, Etienne

    2014-01-01

    In this work, we aim at studying ensemble based optimal control strategies for data assimilation. Such formulation nicely combines the ingredients of ensemble Kalman filters and variational data assimilation (4DVar). In the same way as variational assimilation schemes, it is formulated as the minimization of an objective function, but similarly to ensemble filter, it introduces in its objective function an empirical ensemble-based background-error covariance and works in an off-line smoothing...

  20. Black Hole Statistical Mechanics and The Angular Velocity Ensemble

    CERN Document Server

    Thomson, Mitchell

    2012-01-01

    An new ensemble - the angular velocity ensemble - is derived using Jaynes' method of maximising entropy subject to prior information constraints. The relevance of the ensemble to black holes is motivated by a discussion of external parameters in statistical mechanics and their absence from the Hamiltonian of general relativity. It is shown how this leads to difficulty in deriving entropy as a function of state and recovering the first law of thermodynamics from the microcanonical and canonical ensembles applied to black holes.

  1. ISO 14006. Experiencias previas de estudios de arquitectura que han adoptado el estándar de ecodiseño UNE 150301:2003

    Directory of Open Access Journals (Sweden)

    Arana-Landín, G.

    2012-09-01

    Full Text Available This paper aims to analyze the pioneer UNE 150301 standard, as well as its adoption process and its practical results in the sector of architecture studios. First, the structure, the aim and the scope of norm UNE 150301 have been analysed. Second, the standard's implementation has been examined, concluding that 73% of the companies that have obtained the certificate are architecture studios. A case study has therefore been carried out with the participation of five architecture studios pioneers. These experiences have let us know the main aspects and difficulties of the process. In conclusion, the adoption of the standard UNE 150301 can be a helpful tool in order to reduce the environmental impact of the products and obtain some competitive advantages such as cost reduction, improvement in energy efficiency of the product and a better adaptation to acts and regulations.

    En este artículo se analiza la experiencia de implantación de la norma UNE 150301 de ecodiseño en el sector de los estudios de arquitectura. Tras el examen de la estructura de norma UNE 150301, de sus objetivos y de su alcance, se analiza su difusión, destacándose que el 73% de las empresas certificadas en España son estudios de arquitectura. A continuación se estudia el proceso de implantación real, mediante el estudio de caso que lo analiza en cinco estudios de arquitectura. El estudio realizado permite conocer de primera mano las principales claves y dificultades del proceso de implantación del estándar, así como los resultados obtenidos, entre los que destaca una reducción del impacto ambiental. Se constata, en suma, que la norma UNE 150301 es una herramienta que puede proporcionar ventajas competitivas interesantes a las empresas del sector de los estudios de arquitectura.

  2. Ensembles of signal transduction models using Pareto Optimal Ensemble Techniques (POETs).

    Science.gov (United States)

    Song, Sang Ok; Chakrabarti, Anirikh; Varner, Jeffrey D

    2010-07-01

    Mathematical modeling of complex gene expression programs is an emerging tool for understanding disease mechanisms. However, identification of large models sometimes requires training using qualitative, conflicting or even contradictory data sets. One strategy to address this challenge is to estimate experimentally constrained model ensembles using multiobjective optimization. In this study, we used Pareto Optimal Ensemble Techniques (POETs) to identify a family of proof-of-concept signal transduction models. POETs integrate Simulated Annealing (SA) with Pareto optimality to identify models near the optimal tradeoff surface between competing training objectives. We modeled a prototypical-signaling network using mass-action kinetics within an ordinary differential equation (ODE) framework (64 ODEs in total). The true model was used to generate synthetic immunoblots from which the POET algorithm identified the 117 unknown model parameters. POET generated an ensemble of signaling models, which collectively exhibited population-like behavior. For example, scaled gene expression levels were approximately normally distributed over the ensemble following the addition of extracellular ligand. Also, the ensemble recovered robust and fragile features of the true model, despite significant parameter uncertainty. Taken together, these results suggest that experimentally constrained model ensembles could capture qualitatively important network features without exact parameter information.

  3. Data assimilation in integrated hydrological modeling using ensemble Kalman filtering

    DEFF Research Database (Denmark)

    Rasmussen, Jørn; Madsen, H.; Jensen, Karsten Høgh;

    2015-01-01

    Groundwater head and stream discharge is assimilated using the ensemble transform Kalman filter in an integrated hydrological model with the aim of studying the relationship between the filter performance and the ensemble size. In an attempt to reduce the required number of ensemble members...

  4. A COMPREHENSIVE EVOLUTIONARY APPROACH FOR NEURAL NETWORK ENSEMBLES AUTOMATIC DESIGN

    OpenAIRE

    Bukhtoyarov, V.; Semenkin, E.

    2010-01-01

    A new comprehensive approach for neural network ensembles design is proposed. It consists of a method of neural networks automatic design and a method of automatic formation of an ensemble solution on the basis of separate neural networks solutions. It is demonstrated that the proposed approach is not less effective than a number of other approaches for neural network ensembles design.

  5. Le rêve d'une fille

    Institute of Scientific and Technical Information of China (English)

    袁凤

    2011-01-01

    Un jour,après un cours de géographie dans un collège,une petite fille de 13 ans a transformé son argent de poche en une carte du monde dans une librairie.Elle l'a collée sur le mur devant le lit dans sa chambre.Ce monde sur papier entrait dans ses yeux dès qu'elle les ouvrait chaque matin.Elle marquait d'une étoile le pays sur cette carte du monde chaque fois qu'elle l'avait visité.Le rêve de faire un voyage dans le monde entier lui est venu à l'esprit,et est ainsi devenu une force tout au long de son parcours.

  6. Constitution d'une légende hagiographique : le " martyre " d'Irénée de Lyon

    OpenAIRE

    Decourt, Jean-Claude

    2009-01-01

    La présente contribution reprend l'ensemble du corpus des textes grecs et latins concernant la tradition du martyre d'Irénée de Lyon et tente de montrer que cette dernière est une construction tardive, à la fois littéraire et hagiographique reposant sur deux autres événements historiques, le martyre des Quarante-Huit en 177 et la bataille de Lyon entre Sévère et Albin en 197, confondus et remaniés. This paper gathers all the Greek and Latin testimonia which deal with the so-called martyrdo...

  7. Jalons pour une anthropologie de l’éthique entrepreneuriale en Asie du Sud-Est Groundwork for an Anthropology of Entrepreneurial Ethics in South-East Asia

    OpenAIRE

    Ghislaine Gallenga; Jérôme Soldani

    2013-01-01

    L’éthique entrepreneuriale est une notion largement mobilisée dans le milieu des affaires et des entreprises en Asie du Sud-Est où elle est présentée le plus souvent comme un ensemble de préceptes moraux, idéologiques ou religieux que les acteurs locaux rassemblent sous le vocable « valeurs asiatiques ». L’objet de cette introduction est de replacer ces valeurs dans le contexte de l’entreprise à partir de quelques travaux fondateurs de ce sujet en Asie du Sud-Est. Nous verrons que le plus sou...

  8. Un « Nouvel hygiénisme » ? Le bruit, l’odeur et l’émergence d’une new middle class

    Directory of Open Access Journals (Sweden)

    Laurent Matthey

    2005-10-01

    Full Text Available La tentation est grande aujourd’hui d’envisager un « Nouvel hygiénisme » qui façonnerait les espaces urbains et les corps. Cet article défend cependant l’hypothèse que ce qu’il est convenu d’appeler « Nouvel hygiénisme » est en fait un ensemble de pratiques sociales qui reposent sur la consommation ostentatoire et la distinction sociologique d’une classe sociale en ascension (la new middle class.

  9. Débat : Un «nouvel hygiénisme» ? Le bruit, l'odeur et l'émergence d'une new middle class

    Directory of Open Access Journals (Sweden)

    Walther, Olivier

    2005-10-01

    Full Text Available La tentation est grande aujourd'hui d'envisager un «Nouvel hygiénisme» qui façonnerait les espaces urbains et les corps. Cet article défend cependant l'hypothèse que ce qu'il est convenu d'appeler «Nouvel hygiénisme» est en fait un ensemble de pratiques sociales qui reposent sur la consommation ostentatoire et la distinction sociologique d'une classe sociale en ascension (la new middle class.

  10. Le soja local en Allemagne, une demande soutenue, une offre qui s’étoffe

    Directory of Open Access Journals (Sweden)

    Recknagel Jürgen

    2015-09-01

    Full Text Available Depuis 2009, la sole de soja ne cesse d’augmenter en Allemagne, surtout dans le sud du pays mais aussi à l’est et un peu partout dans les régions au climat propice. Un programme national a permis de créer les références nécessaires pour un conseil qualifié apporté aux agriculteurs via un réseau de développement. Ainsi toute une filière soja est déjà bien avancée dans le sud et en cours de mise en place dans le reste du pays, pour organiser la collecte auprès des producteurs et obtenir une offre groupée pour les transformateurs pour l’alimentation animale et humaine. Le soja allemand ne veut pas rivaliser avec le soja OGM ni pour instant avec le soja non-OGM des Amériques mais vise plutôt les filières courtes régionales et le marché bio qui est encore plus déficitaire en auto-approvisionnement que le conventionnel. Avec 10 000 ha en 2014, dont 25 % en bio, le soja en Allemagne est encore loin de la surface du maïs grain (2008–2014 autour de 500 000 ha. En pratique, 20 % de ces surfaces de maïs au climat a priori propice pourraient représenter le potentiel réel pour le soja en Allemagne, sous condition de prix garantissant une rentabilité suffisante par rapport aux autres grandes cultures. Pour les programmes non-OGM des grands distributeurs, il faut de toute façon une base de production élargie comme celle proposée par l’initiative Danube-Soja, qui dans une version Europe-Soja engloberait aussi la France. Avec le verdissement de la PAC et la montée du cours du Dollar par rapport à l’Euro, les perspectives pour une augmentation de la surface de production de soja en Allemagne et en Europe paraissent bonnes. Maintenant il faut travailler sur les débouchés pour garantir l’absorption de la production grandissante par les marchés et les consommateurs à tous les niveaux : régional, national et européen.

  11. 77 FR 47117 - Chemical, Biological, Radiological, Nuclear (CBRN) Protective Ensemble Standard, Certification...

    Science.gov (United States)

    2012-08-07

    ... do not wish for it to be posted online, you must include the phrase ``CONFIDENTIAL BUSINESS... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Office... made available for public inspection online. Such information includes personal ]...

  12. Une sémiotique à refaire?

    Directory of Open Access Journals (Sweden)

    Eric Landowski

    2013-12-01

    Full Text Available Le récit, c’est ce qui nous sert à donner un peu de signification et de valeur à la vie, en dépit de ce qu’elle peut avoir d’insignifiant par sa monotonie ou d’insensé par son aspect chaotique. Mais indépendamment des significations portées les récits, il nous arrive parfois, face à autrui, à une oeuvre, à un paysage, d’être saisis par la présence d’un sens qui s’impose à notre intuition bien qu’il n’émane d’aucun discours constitué. Ce sens second, toute une littérature, de Proust à Musil, de Svevo à Woolf, s’est employée à le dire en inventant les formes d’écriture de ce qu’on peut appeler le discours de l’expérience. Distinct du vécu, ce discours a le pouvoir d’en capter le mouvement en restituant la dynamique du rapport aux choses, à autrui, à soi-même sur laquelle se fonde l’expérience du sens dans son émergence en acte. Pour construire une sémiotique qui permette d’en rendre compte, ni la grammaire narrative standard ni ses prolongements relatifs aux passions et à la tensivité ne fournissent les instruments nécessaires. Il convient donc de compléter l’appareil théorique dont nous disposons. C’est ce qui justifie le réexamen critique des notions de narrativité et de discursivité auquel procède cet article, ainsi que la proposition finale d’un modèle tenant compte de la diversité des régimes possibles de production du sens dans l’interaction.

  13. Allergie respiratoire et “sunko”: une association rare, à propos d'une observation

    Science.gov (United States)

    Ngombe, Léon Kabamba; Kangulu, Ignace Bwana; Nzaji, Michel Kabamba

    2014-01-01

    Il est rapporté dans ce texte un cas d'allergie respiratoire ayant fait probablement suite à une consommation d'un tabac sans fumé couramment utilisé en République Démocratique du Congo, le « Sunko ». Une rhinite et un asthme allergiques sont les cas. Cette observation permet d'attirer l'attention du monde scientifique à mettre sur pieds des études concernant la composition et les effets du Sunko pour appréhender cette association, puis d'informer l'opinion sur les dangers que courent les consommateurs de ce type de tabac et de faire la revue de la littérature. PMID:25426218

  14. Quark ensembles with the infinite correlation length

    International Nuclear Information System (INIS)

    A number of exactly integrable (quark) models of quantum field theory with the infinite correlation length have been considered. It has been shown that the standard vacuum quark ensemble—Dirac sea (in the case of the space-time dimension higher than three)—is unstable because of the strong degeneracy of a state, which is due to the character of the energy distribution. When the momentum cutoff parameter tends to infinity, the distribution becomes infinitely narrow, leading to large (unlimited) fluctuations. Various vacuum ensembles—Dirac sea, neutral ensemble, color superconductor, and BCS state—have been compared. In the case of the color interaction between quarks, the BCS state has been certainly chosen as the ground state of the quark ensemble

  15. Rotationally invariant ensembles of integrable matrices

    Science.gov (United States)

    Yuzbashyan, Emil A.; Shastry, B. Sriram; Scaramazza, Jasen A.

    2016-05-01

    We construct ensembles of random integrable matrices with any prescribed number of nontrivial integrals and formulate integrable matrix theory (IMT)—a counterpart of random matrix theory (RMT) for quantum integrable models. A type-M family of integrable matrices consists of exactly N -M independent commuting N ×N matrices linear in a real parameter. We first develop a rotationally invariant parametrization of such matrices, previously only constructed in a preferred basis. For example, an arbitrary choice of a vector and two commuting Hermitian matrices defines a type-1 family and vice versa. Higher types similarly involve a random vector and two matrices. The basis-independent formulation allows us to derive the joint probability density for integrable matrices, similar to the construction of Gaussian ensembles in the RMT.

  16. Ensemble Forecasting of Major Solar Flares

    CERN Document Server

    Guerra, J A; Uritsky, V M

    2015-01-01

    We present the results from the first ensemble prediction model for major solar flares (M and X classes). Using the probabilistic forecasts from three models hosted at the Community Coordinated Modeling Center (NASA-GSFC) and the NOAA forecasts, we developed an ensemble forecast by linearly combining the flaring probabilities from all four methods. Performance-based combination weights were calculated using a Monte Carlo-type algorithm by applying a decision threshold $P_{th}$ to the combined probabilities and maximizing the Heidke Skill Score (HSS). Using the probabilities and events time series from 13 recent solar active regions (2012 - 2014), we found that a linear combination of probabilities can improve both probabilistic and categorical forecasts. Combination weights vary with the applied threshold and none of the tested individual forecasting models seem to provide more accurate predictions than the others for all values of $P_{th}$. According to the maximum values of HSS, a performance-based weights ...

  17. Ensemble annealing of complex physical systems

    CERN Document Server

    Habeck, Michael

    2015-01-01

    Algorithms for simulating complex physical systems or solving difficult optimization problems often resort to an annealing process. Rather than simulating the system at the temperature of interest, an annealing algorithm starts at a temperature that is high enough to ensure ergodicity and gradually decreases it until the destination temperature is reached. This idea is used in popular algorithms such as parallel tempering and simulated annealing. A general problem with annealing methods is that they require a temperature schedule. Choosing well-balanced temperature schedules can be tedious and time-consuming. Imbalanced schedules can have a negative impact on the convergence, runtime and success of annealing algorithms. This article outlines a unifying framework, ensemble annealing, that combines ideas from simulated annealing, histogram reweighting and nested sampling with concepts in thermodynamic control. Ensemble annealing simultaneously simulates a physical system and estimates its density of states. The...

  18. Face Recognition using Optimal Representation Ensemble

    CERN Document Server

    Li, Hanxi; Gao, Yongsheng

    2011-01-01

    Recently, the face recognizers based on linear representations have been shown to deliver state-of-the-art performance. In real-world applications, however, face images usually suffer from expressions, disguises and random occlusions. The problematic facial parts undermine the validity of the linear-subspace assumption and thus the recognition performance deteriorates significantly. In this work, we address the problem in a learning-inference-mixed fashion. By observing that the linear-subspace assumption is more reliable on certain face patches rather than on the holistic face, some Bayesian Patch Representations (BPRs) are randomly generated and interpreted according to the Bayes' theory. We then train an ensemble model over the patch-representations by minimizing the empirical risk w.r.t the "leave-one-out margins". The obtained model is termed Optimal Representation Ensemble (ORE), since it guarantees the optimality from the perspective of Empirical Risk Minimization. To handle the unknown patterns in tes...

  19. Statistical ensembles for money and debt

    Science.gov (United States)

    Viaggiu, Stefano; Lionetto, Andrea; Bargigli, Leonardo; Longo, Michele

    2012-10-01

    We build a statistical ensemble representation of two economic models describing respectively, in simplified terms, a payment system and a credit market. To this purpose we adopt the Boltzmann-Gibbs distribution where the role of the Hamiltonian is taken by the total money supply (i.e. including money created from debt) of a set of interacting economic agents. As a result, we can read the main thermodynamic quantities in terms of monetary ones. In particular, we define for the credit market model a work term which is related to the impact of monetary policy on credit creation. Furthermore, with our formalism we recover and extend some results concerning the temperature of an economic system, previously presented in the literature by considering only the monetary base as a conserved quantity. Finally, we study the statistical ensemble for the Pareto distribution.

  20. Eigenstate Gibbs Ensemble in Integrable Quantum Systems

    CERN Document Server

    Nandy, Sourav; Das, Arnab; Dhar, Abhishek

    2016-01-01

    The Eigenstate Thermalization Hypothesis implies that for a thermodynamically large system in one of its eigenstates, the reduced density matrix describing any finite subsystem is determined solely by a set of {\\it relevant} conserved quantities. In a generic system, only the energy plays that role and hence eigenstates appear locally thermal. Integrable systems, on the other hand, possess an extensive number of such conserved quantities and hence the reduced density matrix requires specification of an infinite number of parameters (Generalized Gibbs Ensemble). However, here we show by unbiased statistical sampling of the individual eigenstates with a given finite energy density, that the local description of an overwhelming majority of these states of even such an integrable system is actually Gibbs-like, i.e. requires only the energy density of the eigenstate. Rare eigenstates that cannot be represented by the Gibbs ensemble can also be sampled efficiently by our method and their local properties are then s...

  1. Une nouvelle vague de violence à Gaza

    OpenAIRE

    Lutz, Fanny

    2014-01-01

    Depuis les premiers vents de révoltes début 2011, Israël apparaissait presque comme un petit îlot tranquille au milieu d’un océan arabe mouvementé. Les événements de ces derniers jours ont brusquement replacé l’Etat hébreu au coeur de l’actualité régionale et internationale ; les médias et les réseaux sociaux diffusent une haine raciale exacerbée tandis que les roquettes bombardent Israël, en réponse de quoi les raids israéliens pilonnent la bande de Gaza. Après « Plomb durci » en 2008 et « P...

  2. Aleph : anatomie d'une experience

    CERN Multimedia

    Lynn Silverman

    1993-01-01

    "Aleph, anatomie d'une expérience" est un documentaire ethnologique sur les techniciens et les chercheurs de la physique des particules du Centre européen de recherche nucléaire, le CERN, près de Genève. Le film, dont le tournage s'est échelonné sur quatre années, de 1987 à 1991, retrace les différentes étapes de la mise en œuvre, sur le nouvel accélérateur (le LEP) du projet Aleph ; la construction des différents constituants du détecteur dans les centres de recherche de l'Europe entière, leur arrivée au CERN, l'assemblage… jusqu'à l'annonce des premiers résultats, obtenus en 1990.

  3. Une terreur par l’image

    OpenAIRE

    DULONG, Annie

    2011-01-01

    Si d’autres événements — Hiroshima, la découverte des camps de concentration, la chute du mur de Berlin — ont, au cours du XXe siècle, marqué suffisamment l’imaginaire pour trouver leur réponse dans des œuvres d’art, le 11 septembre 2001 pose la question de la fictionnalisation autrement : il ne s’agit plus tant de combler les manques de la représentation, liés à l’absence d’images ou au délai dans leur dévoilement, mais bien de composer avec l’omniprésence d’une représentation martelée à la ...

  4. Vers une illusio sans illusion ?

    Directory of Open Access Journals (Sweden)

    Pascal Durand

    2011-09-01

    Full Text Available À Daniel Giovannangeli« Peu importe la direction du vent, le soleil va toujours là où il doit aller. »Proverbe congolais« Une carrière ne se propose aux lettres, mais on use du mot à la façon de lyriques célébrant le parcours de l’astre jusqu’à sa hauteur accoutumée — que, tout à l’heure, il va toucher — ascension pas avancement. »Mallarmé, ConfrontationDe l’illusio en général et de l’illusio littéraire en particulierPar stratégie, terme quelque peu abandonné ensuite, de même que celui d’inté...

  5. Fragmenter une activité à risque

    OpenAIRE

    Salies, Evens; Mondello, Gérard

    2007-01-01

    La libéralisation de l'activité d'un secteur économique à céder des actifs des entreprises historiques à de nouveaux entrants. Dans cet article, nous montrerons que lorsqu'il s'agit d'une activité à risque, le gain de la fragmentation de cette activité ne peut être évalué sans prendre en compte l'impact en termes de sureté.Pour cela nous utilisons le concept de dominance stochastique que nous appliquons à la comparaison des coûts espérés, avant et après fragmentation. Les résultats obtenus so...

  6. Ensemble Robustness of Deep Learning Algorithms

    OpenAIRE

    Feng, Jiashi; Zahavy, Tom; Kang, Bingyi; Xu, Huan; Mannor, Shie

    2016-01-01

    The question why deep learning algorithms perform so well in practice has attracted increasing research interest. However, most of well-established approaches, such as hypothesis capacity, robustness or sparseness, have not provided complete explanations, due to the high complexity of the deep learning algorithms and their inherent randomness. In this work, we introduce a new approach~\\textendash~ensemble robustness~\\textendash~towards characterizing the generalization performance of generic ...

  7. Ensemble Data Assimilation: Algorithms and Software

    OpenAIRE

    Nerger, Lars

    2014-01-01

    Ensemble data assimilation is nowadays applied to various problems to estimate a model state and model parameters by combining the model predictions with observational data. At the Alfred Wegener Institute, the assimilation focuses on ocean-sea ice models and coupled ocean-biogeochemical models. The high dimension of realistic models requires particularly efficient algorithms that are also usable on supercomputers. For the application of such filters, the Parallel Data Assimilation Framework ...

  8. Analysis and optimization of weighted ensemble sampling

    CERN Document Server

    Aristoff, David

    2016-01-01

    We give a mathematical framework for weighted ensemble (WE) sampling, a binning and resampling technique for efficiently computing probabilities in molecular dynamics. We prove that WE sampling is unbiased in a very general setting that includes adaptive binning. We show that when WE is used for stationary calculations in tandem with a Markov state model (MSM), the MSM can be used to optimize the allocation of replicas in the bins.

  9. Staying Thermal with Hartree Ensemble Approximations

    CERN Document Server

    Salle, M; Vink, Jeroen C

    2000-01-01

    Using Hartree ensemble approximations to compute the real time dynamics of scalar fields in 1+1 dimension, we find that with suitable initial conditions, approximate thermalization is achieved much faster than found in our previous work. At large times, depending on the interaction strength and temperature, the particle distribution slowly changes: the Bose-Einstein distribution of the particle densities develops classical features. We also discuss variations of our method which are numerically more efficient.

  10. Support Vector Machine Ensemble Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    LI Ye; YIN Ru-po; CAI Yun-ze; XU Xiao-ming

    2006-01-01

    Support vector machines (SVMs) have been introduced as effective methods for solving classification problems.However, due to some limitations in practical applications,their generalization performance is sometimes far from the expected level. Therefore, it is meaningful to study SVM ensemble learning. In this paper, a novel genetic algorithm based ensemble learning method, namely Direct Genetic Ensemble (DGE), is proposed. DGE adopts the predictive accuracy of ensemble as the fitness function and searches a good ensemble from the ensemble space. In essence, DGE is also a selective ensemble learning method because the base classifiers of the ensemble are selected according to the solution of genetic algorithm. In comparison with other ensemble learning methods, DGE works on a higher level and is more direct. Different strategies of constructing diverse base classifiers can be utilized in DGE.Experimental results show that SVM ensembles constructed by DGE can achieve better performance than single SVMs,bagged and boosted SVM ensembles. In addition, some valuable conclusions are obtained.

  11. Deux comparatismes pour une anthropologie historique

    Directory of Open Access Journals (Sweden)

    Pierre-Olivier Dittmar

    2010-06-01

    Full Text Available Malgré des appels répétés depuis plus d’un siècle de la part des historiens, le comparatisme, qui est un élément majeur de l’anthropologie, demeure très peu pratiqué. Ce rejet est ici analysé comme un refus d’une quête des invariants de l’homme qui aboutirait à des résultats an-historiques. Un autre comparatisme est cependant possible, qui instrumentalise la confrontation des univers pour mieux relever les différences. C’est les conditions et les avantages d’une telle pratique qui sont ici exposés, à partir de l’exemple des tabous alimentaires.Despite the repeated calls by some historians for more than a century, many seldom practice a major element of anthropology: comparativism. This paper will analyze this rejection as a refusal to investigate the constants of the human experience that lead to a-historical conclusions. However, another kind of comparativism is possible, one that examines the contrast between cultures in order to better understand their differences. Using the case of dietary taboos, this paper will look at the conditions and advantages of such a practice.Nonostante i molteplici appelli da più di un secolo da parte degli storici, il comparatismo, che costituisce un elemento fondamentale dell’antropologia, è ancora oggi troppo poco spesso praticato. Si proporrà di interpretare questo rifiuto come un rifiuto della ricerca di invarianti umane che condurrebbe a risultati a-storici. Un’altra forma di comparatismo è nondimeno possibile, una forma precisamente che ricorre al confronto di universi diversi per meglio comprenderne le difference reciproche. L’articolo espone le condizioni e i vantaggi di questa metodologia di ricerca, a partire dall’esempio degli interdetti alimentari.

  12. Spatially Coupled Ensembles Universally Achieve Capacity under Belief Propagation

    CERN Document Server

    Kudekar, Shrinivas; Urbanke, Ruediger

    2012-01-01

    We investigate spatially coupled code ensembles. For transmission over the binary erasure channel, it was recently shown that spatial coupling increases the belief propagation threshold of the ensemble to essentially the maximum a-priori threshold of the underlying component ensemble. This explains why convolutional LDPC ensembles, originally introduced by Felstrom and Zigangirov, perform so well over this channel. We show that the equivalent result holds true for transmission over general binary-input memoryless output-symmetric channels. More precisely, given a desired error probability and a gap to capacity, we can construct a spatially coupled ensemble which fulfills these constraints universally on this class of channels under belief propagation decoding. In fact, most codes in that ensemble have that property. The quantifier universal refers to the single ensemble/code which is good for all channels but we assume that the channel is known at the receiver. The key technical result is a proof that under b...

  13. Various multistage ensembles for prediction of heating energy consumption

    Directory of Open Access Journals (Sweden)

    Radisa Jovanovic

    2015-04-01

    Full Text Available Feedforward neural network models are created for prediction of daily heating energy consumption of a NTNU university campus Gloshaugen using actual measured data for training and testing. Improvement of prediction accuracy is proposed by using neural network ensemble. Previously trained feed-forward neural networks are first separated into clusters, using k-means algorithm, and then the best network of each cluster is chosen as member of an ensemble. Two conventional averaging methods for obtaining ensemble output are applied; simple and weighted. In order to achieve better prediction results, multistage ensemble is investigated. As second level, adaptive neuro-fuzzy inference system with various clustering and membership functions are used to aggregate the selected ensemble members. Feedforward neural network in second stage is also analyzed. It is shown that using ensemble of neural networks can predict heating energy consumption with better accuracy than the best trained single neural network, while the best results are achieved with multistage ensemble.

  14. Multivariate localization methods for ensemble Kalman filtering

    KAUST Repository

    Roh, S.

    2015-12-03

    In ensemble Kalman filtering (EnKF), the small number of ensemble members that is feasible to use in a practical data assimilation application leads to sampling variability of the estimates of the background error covariances. The standard approach to reducing the effects of this sampling variability, which has also been found to be highly efficient in improving the performance of EnKF, is the localization of the estimates of the covariances. One family of localization techniques is based on taking the Schur (element-wise) product of the ensemble-based sample covariance matrix and a correlation matrix whose entries are obtained by the discretization of a distance-dependent correlation function. While the proper definition of the localization function for a single state variable has been extensively investigated, a rigorous definition of the localization function for multiple state variables that exist at the same locations has been seldom considered. This paper introduces two strategies for the construction of localization functions for multiple state variables. The proposed localization functions are tested by assimilating simulated observations experiments into the bivariate Lorenz 95 model with their help.

  15. Gradient Flow Analysis on MILC HISQ Ensembles

    CERN Document Server

    Bazavov, A; Brown, N; DeTar, C; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Komijani, J; Laiho, J; Levkova, L; Oktay, M; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2014-01-01

    We report on a preliminary scale determination with gradient-flow techniques on the $N_f = 2 + 1 + 1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ are computed using Symanzik flow and the cloverleaf definition of $\\langle E \\rangle$ on each ensemble. Then both scales and the meson masses $aM_\\pi$ and $aM_K$ are adjusted for mistunings in the charm mass. Using a combination of continuum chiral perturbation theory and a Taylor series ansatz in the lattice spacing, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. Our preliminary results are $\\sqrt{t_0} = 0.1422(7)$fm and $w_0 = 0.1732(10)$fm. We also find the continuum mass-dependence of $w_0$.

  16. Ras Conformational Ensembles, Allostery, and Signaling.

    Science.gov (United States)

    Lu, Shaoyong; Jang, Hyunbum; Muratcioglu, Serena; Gursoy, Attila; Keskin, Ozlem; Nussinov, Ruth; Zhang, Jian

    2016-06-01

    Ras proteins are classical members of small GTPases that function as molecular switches by alternating between inactive GDP-bound and active GTP-bound states. Ras activation is regulated by guanine nucleotide exchange factors that catalyze the exchange of GDP by GTP, and inactivation is terminated by GTPase-activating proteins that accelerate the intrinsic GTP hydrolysis rate by orders of magnitude. In this review, we focus on data that have accumulated over the past few years pertaining to the conformational ensembles and the allosteric regulation of Ras proteins and their interpretation from our conformational landscape standpoint. The Ras ensemble embodies all states, including the ligand-bound conformations, the activated (or inactivated) allosteric modulated states, post-translationally modified states, mutational states, transition states, and nonfunctional states serving as a reservoir for emerging functions. The ensemble is shifted by distinct mutational events, cofactors, post-translational modifications, and different membrane compositions. A better understanding of Ras biology can contribute to therapeutic strategies. PMID:26815308

  17. Gradient Flow Analysis on MILC HISQ Ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nathan [Washington U., St. Louis; Bazavov, Alexei [Brookhaven; Bernard, Claude [Washington U., St. Louis; DeTar, Carleton [Utah U.; Foley, Justin [Utah U.; Gottlieb, Steven [Indiana U.; Heller, Urs M. [APS, New York; Hetrick, J. E. [U. Pacific, Stockton; Komijani, Javad [Washington U., St. Louis; Laiho, Jack [Syracuse U.; Levkova, Ludmila [Utah U.; Oktay, M. B. [Utah U.; Sugar, Robert [UC, Santa Barbara; Toussaint, Doug [Arizona U.; Van de Water, Ruth S. [Fermilab; Zhou, Ran [Fermilab

    2014-11-14

    We report on a preliminary scale determination with gradient-flow techniques on the $N_f = 2 + 1 + 1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ are computed using Symanzik flow and the cloverleaf definition of $\\langle E \\rangle$ on each ensemble. Then both scales and the meson masses $aM_\\pi$ and $aM_K$ are adjusted for mistunings in the charm mass. Using a combination of continuum chiral perturbation theory and a Taylor series ansatz in the lattice spacing, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. Our preliminary results are $\\sqrt{t_0} = 0.1422(7)$fm and $w_0 = 0.1732(10)$fm. We also find the continuum mass-dependence of $w_0$.

  18. Multivariate localization methods for ensemble Kalman filtering

    Directory of Open Access Journals (Sweden)

    S. Roh

    2015-05-01

    Full Text Available In ensemble Kalman filtering (EnKF, the small number of ensemble members that is feasible to use in a practical data assimilation application leads to sampling variability of the estimates of the background error covariances. The standard approach to reducing the effects of this sampling variability, which has also been found to be highly efficient in improving the performance of EnKF, is the localization of the estimates of the covariances. One family of localization techniques is based on taking the Schur (entry-wise product of the ensemble-based sample covariance matrix and a correlation matrix whose entries are obtained by the discretization of a distance-dependent correlation function. While the proper definition of the localization function for a single state variable has been extensively investigated, a rigorous definition of the localization function for multiple state variables has been seldom considered. This paper introduces two strategies for the construction of localization functions for multiple state variables. The proposed localization functions are tested by assimilating simulated observations experiments into the bivariate Lorenz 95 model with their help.

  19. Multivariate localization methods for ensemble Kalman filtering

    KAUST Repository

    Roh, S.

    2015-05-08

    In ensemble Kalman filtering (EnKF), the small number of ensemble members that is feasible to use in a practical data assimilation application leads to sampling variability of the estimates of the background error covariances. The standard approach to reducing the effects of this sampling variability, which has also been found to be highly efficient in improving the performance of EnKF, is the localization of the estimates of the covariances. One family of localization techniques is based on taking the Schur (entry-wise) product of the ensemble-based sample covariance matrix and a correlation matrix whose entries are obtained by the discretization of a distance-dependent correlation function. While the proper definition of the localization function for a single state variable has been extensively investigated, a rigorous definition of the localization function for multiple state variables has been seldom considered. This paper introduces two strategies for the construction of localization functions for multiple state variables. The proposed localization functions are tested by assimilating simulated observations experiments into the bivariate Lorenz 95 model with their help.

  20. Quantum statistical ensemble for emissive correlated systems

    Science.gov (United States)

    Shakirov, Alexey M.; Shchadilova, Yulia E.; Rubtsov, Alexey N.

    2016-06-01

    Relaxation dynamics of complex quantum systems with strong interactions towards the steady state is a fundamental problem in statistical mechanics. The steady state of subsystems weakly interacting with their environment is described by the canonical ensemble which assumes the probability distribution for energy to be of the Boltzmann form. The emergence of this probability distribution is ensured by the detailed balance of the transitions induced by the interaction with the environment. Here we consider relaxation of an open correlated quantum system brought into contact with a reservoir in the vacuum state. We refer to such a system as emissive since particles irreversibly evaporate into the vacuum. The steady state of the system is a statistical mixture of the stable eigenstates. We found that, despite the absence of the detailed balance, the stationary probability distribution over these eigenstates is of the Boltzmann form in each N -particle sector. A quantum statistical ensemble corresponding to the steady state is characterized by different temperatures in the different sectors, in contrast to the Gibbs ensemble. We investigate the transition rates between the eigenstates to understand the emergence of the Boltzmann distribution and find their exponential dependence on the transition energy. We argue that this property of transition rates is generic for a wide class of emissive quantum many-body systems.

  1. Renewable Energy Certificate Program

    Energy Technology Data Exchange (ETDEWEB)

    Gwendolyn S. Andersen

    2012-07-17

    This project was primarily to develop and implement a curriculum which will train undergraduate and graduate students at the University seeking a degree as well as training for enrollees in a special certification program to prepare individuals to be employed in a broad range of occupations in the field of renewable energy and energy conservation. Curriculum development was by teams of Saint Francis University Faculty in the Business Administration and Science Departments and industry experts. Students seeking undergraduate and graduate degrees are able to enroll in courses offered within these departments which will combine theory and hands-on training in the various elements of wind power development. For example, the business department curriculum areas include economic modeling, finance, contracting, etc. The science areas include meteorology, energy conversion and projection, species identification, habitat protection, field data collection and analysis, etc.

  2. Ensemble Data Assimilation Without Ensembles: Methodology and Application to Ocean Data Assimilation

    Science.gov (United States)

    Keppenne, Christian L.; Rienecker, Michele M.; Kovach, Robin M.; Vernieres, Guillaume

    2013-01-01

    Two methods to estimate background error covariances for data assimilation are introduced. While both share properties with the ensemble Kalman filter (EnKF), they differ from it in that they do not require the integration of multiple model trajectories. Instead, all the necessary covariance information is obtained from a single model integration. The first method is referred-to as SAFE (Space Adaptive Forecast error Estimation) because it estimates error covariances from the spatial distribution of model variables within a single state vector. It can thus be thought of as sampling an ensemble in space. The second method, named FAST (Flow Adaptive error Statistics from a Time series), constructs an ensemble sampled from a moving window along a model trajectory. The underlying assumption in these methods is that forecast errors in data assimilation are primarily phase errors in space and/or time.

  3. Gestion de production en systèmes d'élevage utilisateurs d'herbe : une approche par atelier

    OpenAIRE

    Coleno, Francois-Christophe; Duru, Michel

    1998-01-01

    International audience La diversité des systèmes d'élevage basés sur l'utilisation de l'herbe induit une diversité de formes d'adaptation de ces systèmes aux mesures et réglementations portant sur les produits ou le territoire. Ces différences tiennent autant aux caractéristiques du matériel biologique qu'aux spécificités des moyens de production. Pour aider les éleveurs à transformer un projet de production en programme d'action, c'est donc un ensemble de contraintes liées à ces caractéri...

  4. Méthodologie de l'étude endocrinienne d'une espèce sauvage, l'Anguille

    Directory of Open Access Journals (Sweden)

    DUFOUR S.

    1994-10-01

    C'est la mise en oeuvre de tout un ensemble de méthodes d'investigation, allant de la mise au point des outils moléculaires (purifications d'hormones, obtention d'anticorps, dosages immunologiques, clonage, obtention de sondes... à la réalisation d'expériences in vitro (cultures de cellules, incubation ou périfusion d'organes et in vivo (ablations de glandes, traitements hormonaux, prélèvements sanguins... juqu'aux études sur le terrain, qui permet une approche complète et intégrée de l'endocrinologie de ce poisson.

  5. Les sciences de l’information et de la communication : une discipline Gender blind ?

    OpenAIRE

    Coulomb-Gully, Marlène

    2012-01-01

    Sous le titre un peu provocateur « Les sciences de l’information et de la communication, une discipline Gender blind ? », on s’efforce de faire le point sur les relations entretenues entre sic et études de genre. Après avoir retracé les difficultés d’implantation de ces dernières en France et fait l’hypothèse d’un Gender turn de l’ensemble des sciences humaines et sociales au début des années 2000, on tente d’apprécier la place et l’apport de ce questionnement pour l’interdiscipline. Si les s...

  6. Entre nature et industrie. Une terre d'accueil pour étudiants, commerces et entreprises (Saint-Sulpice, VD)

    OpenAIRE

    Depeursinge, Xavier

    2006-01-01

    Afin de réagir à une situation périphérique actuelle chaotique et de donner réalité aux dispositions du Plan directeur Cantonal, le canton de Vaud a entrepris, avec l'ensemble des communes de Lausanne à Morges, de développer un projet d'urbanisation et de transport à l'échelle de toute l'agglomération. Les mesures envisagées visent à préserver le paysage et à enrayer la dégradation de la mobilité en éradiquant le phénomène d'étalement urbain par la densification des zones urbaines actuelles. ...

  7. Dialysis technicians' perception of certification.

    Science.gov (United States)

    Williams, Helen F; Garbin, Margery

    2015-03-01

    The Nephrology Nursing Certification Commission initiated this research project to study the viewpoint of dialysis technicians regarding the value of certification. A national convenience sample was obtained using both paper-and-pencil and online forms of the survey instrument. Demographic characteristics were obtained concerning age, race, ethnicity, education, and future employment planning. Technicians' primary work settings, the roles they fill, and the types of certification they hold are described. Incentives offered by employers are considered to explore how they contribute to job satisfaction. Understanding the perceptions of technicians regarding the benefits of certification and the limitations of workplace incentives should enable employers to improve their recruitment and retention programs. Information obtained may offer a baseline for future observations of the characteristics of these significant and essential contributors to the nephrology workforce. PMID:26480642

  8. Une recherche collaborative sur l’accompagnement des futurs instituteurs : un levier de développement professionnel pour les maîtres de stage

    OpenAIRE

    Van Nieuwenhoven, Catherine; Colognesi, Stéphane

    2015-01-01

    En Belgique francophone, peu de prescrits balisent l’accompagnement des futurs enseignants en stage tant du côté des superviseurs de l’institut de formation que des maîtres de stage sur le terrain. Les accompagnateurs ne bénéficient pas de formation spécifique pour assurer cette tâche et sont tiraillés entre le suivi formatif qu’ils veulent assurer à leur stagiaire et la tâche d’évaluation certificative liée au contexte de formation à laquelle ils contribuent. Une recherche collaborative a ra...

  9. De praeceptis ferendis: good practice in multi-model ensembles

    Directory of Open Access Journals (Sweden)

    I. Kioutsioukis

    2014-06-01

    Full Text Available Ensembles of air quality models have been formally and empirically shown to outperform single models in many cases. Evidence suggests that ensemble error is reduced when the members form a diverse and accurate ensemble. Diversity and accuracy are hence two factors that should be taken care of while designing ensembles in order for them to provide better predictions. There exists a trade-off between diversity and accuracy for which one cannot be gained without expenses of the other. Theoretical aspects like the bias-variance-covariance decomposition and the accuracy-diversity decomposition are linked together and support the importance of creating ensemble that incorporates both the elements. Hence, the common practice of unconditional averaging of models without prior manipulation limits the advantages of ensemble averaging. We demonstrate the importance of ensemble accuracy and diversity through an inter-comparison of ensemble products for which a sound mathematical framework exists, and provide specific recommendations for model selection and weighting for multi model ensembles. To this end we have devised statistical tools that can be used for diagnostic evaluation of ensemble modelling products, complementing existing operational methods.

  10. Board Certification: The Global Perspective.

    Science.gov (United States)

    Day, Susan H

    2016-09-01

    This article reviews globalization of quality standards in medicine, with emphasis on accreditation and certification. In conjunction with the 100th anniversary of the American Board of Ophthalmology, the author explores globalization movements, standards of quality, expectations of others seeking certification, the American Board of Medical Specialties (ABMS) International, interrelationships with the ABMS, and considerations both pragmatic and philosophical in addressing globalization of standards. PMID:27550006

  11. Quand la biopsie cutanee peut etiqueter une epilepsie

    Directory of Open Access Journals (Sweden)

    Taoufiq Harmouch

    2011-10-01

    Full Text Available La maladie de Lafora (ML represente une forme rare et grave d�epilepsie myoclonique progressive. C�est une affection a transmission autosomique recessive, heterogene sur le plan genetique. Nous rapportons le cas d�une adolescente de 16 ans, issue de parents consanguins de premier degre, qui presente depuis l�age de 14 ans des crises d�epilepsie et des myoclonies. L'examen neurologique a montre un syndrome cerebelleux et une deterioration intellectuelle. La biopsie cutanee etait indispensable pour orienter le diagnostic. La ML a un pronostic constamment fatal. L�etude histologique confirme le diagnostic et l�etude moleculaire peut aider a etablir un conseil genetique.

  12. La classe de langue un lieu ordinaire, une interaction complexe

    OpenAIRE

    Cicurel, Francine

    2005-01-01

    Cet article trace le chemin parcouru dans la compréhension des discours et échanges se produisant dans une classe de langue : depuis une époque (les années SGAV) où on la présentait surtout comme le lieu de réalisation d’une méthodologie d’enseignement, la classe est progressivement devenue le lieu d’observation d’interactions complexes entre les participants, dont on dégagera ici quelques traits. Etre exposé à la langue dans le cadre d’une classe comporte des points communs : un processus in...

  13. Seasonal hydrological ensemble forecasts over Europe

    Science.gov (United States)

    Arnal, Louise; Wetterhall, Fredrik; Stephens, Elisabeth; Cloke, Hannah; Pappenberger, Florian

    2016-04-01

    This study investigates the limits of predictability in dynamical seasonal discharge forecasting, in both space and time, over Europe. Seasonal forecasts have an important socioeconomic value. Applications are numerous and cover hydropower management, spring flood prediction, low flow prediction for navigation and agricultural water demands. Additionally, the constant increase in NWP skill for longer lead times and the predicted increase in the intensity and frequency of hydro-meteorological extremes, have amplified the incentive to promote and further improve hydrological forecasts on sub-seasonal to seasonal timescales. In this study, seasonal hydrological forecasts (SEA), driven by the ECMWF's System 4 in hindcast mode, were analysed against an Ensemble Streamflow Prediction (ESP) benchmark. The ESP was forced with an ensemble of resampled historical meteorological observations and started with perfect initial conditions. Both forecasts were produced by the LISFLOOD model, run on the pan-European scale with a spatial resolution of 5 by 5 km. The forecasts were issued monthly on a daily time step, from 1990 until the current time, up to a lead time of 7 months. The seasonal discharge forecasts were analysed against the ESP on a catchment scale in terms of their accuracy, skill and sharpness, using a diverse set of verification metrics (e.g. KGE, CRPSS and ROC). Additionally, a reverse-ESP was constructed by forcing the LISFLOOD model with a single perfect meteorological set of observations and initiated from an ensemble of resampled historical initial conditions. The comparison of the ESP with the reverse-ESP approach enabled the identification of the respective contribution of meteorological forcings and hydrologic initial conditions errors to seasonal discharge forecasting uncertainties in Europe. These results could help pinpoint target elements of the forecasting chain which, after being improved, could lead to substantial increase in discharge predictability

  14. Cavity-Controlled Chemistry in Molecular Ensembles

    Science.gov (United States)

    Herrera, Felipe; Spano, Frank C.

    2016-06-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space for a wide class of organic molecular species.

  15. Supervised Ensemble Classification of Kepler Variable Stars

    CERN Document Server

    Bass, Gideon

    2016-01-01

    Variable star analysis and classification is an important task in the understanding of stellar features and processes. While historically classifications have been done manually by highly skilled experts, the recent and rapid expansion in the quantity and quality of data has demanded new techniques, most notably automatic classification through supervised machine learning. We present an expansion of existing work on the field by analyzing variable stars in the {\\em Kepler} field using an ensemble approach, combining multiple characterization and classification techniques to produce improved classification rates. Classifications for each of the roughly 150,000 stars observed by {\\em Kepler} are produced separating the stars into one of 14 variable star classes.

  16. Cavity-controlled chemistry in molecular ensembles

    CERN Document Server

    Herrera, Felipe

    2015-01-01

    The demonstration of strong and ultrastrong coupling regimes of cavity QED with polyatomic molecules has opened new routes to control chemical dynamics at the nanoscale. We show that strong resonant coupling of a cavity field with an electronic transition can effectively decouple collective electronic and nuclear degrees of freedom in a disordered molecular ensemble, even for molecules with high-frequency quantum vibrational modes having strong electron-vibration interactions. This type of polaron decoupling can be used to control chemical reactions. We show that the rate of electron transfer reactions in a cavity can be orders of magnitude larger than in free space, for a wide class of organic molecular species.

  17. Probabilistic Flash Flood Forecasting using Stormscale Ensembles

    Science.gov (United States)

    Hardy, J.; Gourley, J. J.; Kain, J. S.; Clark, A.; Novak, D.; Hong, Y.

    2013-12-01

    Flash flooding is one of the most costly and deadly natural hazards in the US and across the globe. The loss of life and property from flash floods could be mitigated with better guidance from hydrological models, but these models have limitations. For example, they are commonly initialized using rainfall estimates derived from weather radars, but the time interval between observations of heavy rainfall and a flash flood can be on the order of minutes, particularly for small basins in urban settings. Increasing the lead time for these events is critical for protecting life and property. Therefore, this study advances the use of quantitative precipitation forecasts (QPFs) from a stormscale NWP ensemble system into a distributed hydrological model setting to yield basin-specific, probabilistic flash flood forecasts (PFFFs). Rainfall error characteristics of the individual members are first diagnosed and quantified in terms of structure, amplitude, and location (SAL; Wernli et al., 2008). Amplitude and structure errors are readily correctable due to their diurnal nature, and the fine scales represented by the CAPS QPF members are consistent with radar-observed rainfall, mainly showing larger errors with afternoon convection. To account for the spatial uncertainty of the QPFs, we use an elliptic smoother, as in Marsh et al. (2012), to produce probabilistic QPFs (PQPFs). The elliptic smoother takes into consideration underdispersion, which is notoriously associated with stormscale ensembles, and thus, is good for targeting the approximate regions that may receive heavy rainfall. However, stormscale details contained in individual members are still needed to yield reasonable flash flood simulations. Therefore, on a case study basis, QPFs from individual members are then run through the hydrological model with their predicted structure and corrected amplitudes, but the locations of individual rainfall elements are perturbed within the PQPF elliptical regions using Monte

  18. Bayesian ensemble refinement by replica simulations and reweighting

    CERN Document Server

    Hummer, Gerhard

    2015-01-01

    We describe different Bayesian ensemble refinement methods, examine their interrelation, and discuss their practical application. With ensemble refinement, the properties of dynamic and partially disordered (bio)molecular structures can be characterized by integrating a wide range of experimental data, including measurements of ensemble-averaged observables. We start from a Bayesian formulation in which the posterior is a functional that ranks different configuration space distributions. By maximizing this posterior, we derive an optimal Bayesian ensemble distribution. For discrete configurations, this optimal distribution is identical to that obtained by the maximum entropy "ensemble refinement of SAXS" (EROS) formulation. Bayesian replica ensemble refinement enhances the sampling of relevant configurations by imposing restraints on averages of observables in coupled replica molecular dynamics simulations. We find that the strength of the restraint scales with the number of replicas and we show that this sca...

  19. A Framework for Non-Equilibrium Statistical Ensemble Theory

    Institute of Scientific and Technical Information of China (English)

    BI Qiao; HE Zu-Tan; LIU Jie

    2011-01-01

    Since Gibbs synthesized a general equilibrium statistical ensemble theory, many theorists have attempted to generalized the Gibbsian theory to non-equilibrium phenomena domain, however the status of the theory of nonequilibrium phenomena can not be said as firm as well established as the Gibbsian ensemble theory. In this work, we present a framework for the non-equilibrium statistical ensemble formalism based on a subdynamic kinetic equation (SKE) rooted from the Brussels-Austin school and followed by some up-to-date works. The constructed key is to use a similarity transformation between Gibbsian ensembles formalism based on Liouville equation and the subdynamic ensemble formalism based on the SKE. Using this formalism, we study the spin-Boson system, as cases of weak coupling or strongly coupling, and obtain the reduced density operators for the Canonical ensembles easily.

  20. Skill forecasting from ensemble predictions of wind power

    DEFF Research Database (Denmark)

    Pinson, Pierre; Nielsen, Henrik Aalborg; Madsen, Henrik;

    2009-01-01

    ensemble predictions are derived from the conversion of ECMWF and NCEP ensemble forecasts of meteorological variables to wind power ensemble forecasts, as well as by a lagged average approach alternative. The ability of prediction risk indices calculated from the various types of ensembles forecasts...... risk indices aiming to give a comprehensive signal on the expected level of forecast uncertainty. Ensemble predictions of wind generation are used as input. A proposal for the definition of prediction risk indices is given. Such skill forecasts are based on the spread of ensemble forecasts (i.e. a set...... of alternative scenarios for the coming period) for a single prediction horizon or over a took-ahead period. It is shown on the test case of a Danish offshore wind farm how these prediction risk indices may be related to several levels of forecast uncertainty (and potential energy imbalances). Wind power...

  1. Certification of training

    Science.gov (United States)

    Gibson, Richard S.

    1994-01-01

    Training has been around as an informal process for countless years. Most higher order animals require some level of training in hunting, social skills, or other survival related skills to continue their existence beyond early infancy. Much of the training is accomplished through imitation, trial and error, and good luck. In some ways the essentials of training in aviation have not deviated from this original formula a great deal. One of the major changes in aviation and other technical areas is that more complex response chains based on a broader base of knowledge are now required. 'To certify' means many things according to the American Heritage dictionary of the English Language. These meanings range from 'to guarantee as meeting a standard' to 'to declare legally insane'. For this discussion, we will use the definition 'an action taken by some authoritative body that essentially guarantees that the instruction meets some defined standard'. In order to make this certification, the responsible body subjects the educational process, training, training device, or simulator to some type of examination to determine its adequacy or validity.

  2. Dorothée, une machine pour récupérer le pétrole.

    CERN Document Server

    CERN Video Productions

    2010-01-01

    Dorothée est constituée de deux cylindres contrarotatifs montés parallèlement et formant aussi des flotteurs (diamètre 30 cm, longueur 2 m). La rotation motorisée des cylindres (par air comprimé pour une question de risque d'explosion) entraîne un film d'hydrocarbure. Le film adhérant sur les cylindres rotatifs est alors intercepté par un racleur qui le dévie dans un bac de récupération fixé au centre de la machine (80 litres) et qui est vidangé gravitairement et en permanence par une pompe immergée. Selon la viscosité des hydrocarbures, le débit de récupération est de 500 à 1000 litres par heure. L'ensemble en alliage d’aluminium flotte sur l'eau (200 kg) et est protégé par un capot pour éviter que des vagues d'eau viennent tomber dans le bac de récupération.

  3. La Chine en quête d'une « société harmonieuse »

    Directory of Open Access Journals (Sweden)

    Amandine Monteil

    2012-01-01

    Full Text Available Erigée en « championne des Objectifs du millénaire pour le développement » de par sa contribution majeure au recul de l'effectif de population en situation de grande pauvreté dans le monde, la Chine est plus que jamais confrontée à d'importants défis sociaux : chômage, condition des migrants ruraux, application de standards minimaux de travail décent, mise en place d'un système de protection sociale couvrant l'ensemble de la population... Il y a trente ans, « permettre à quelques-uns de s'enrichir en premier » avait été encouragé dans l'espoir de créer un effet d'entraînement susceptible de produire les conditions d'une prospérité générale. Face à l'aggravation des inégalités, l'accent a été mis sur le rééquilibrage du modèle de développement chinois et la « construction d'une société harmonieuse », passant notamment par la mise en œuvre de nouvelles politiques sociales, voire par la collaboration entre les autorités locales et le « tiers secteur ».

  4. Vers une narratologie naturelle de la musique

    Directory of Open Access Journals (Sweden)

    Nicolas Marty

    2011-12-01

    Full Text Available Grâce à l’étude du modèle de la narratologie « naturelle » de Monika Fludernik, nous souhaitons montrer qu’il est possible d’envisager une narratologie « naturelle » de la musique, prenant en compte tous les phénomènes sémiotiques, sémantiques et narratifs présents dans l’écoute de la musique. Nous ouvrons de plus la question de la différence observable entre les « narrativisations » opérées par les musiciens experts et celles opérées par les non-experts.Following Monika Fludernik’s frame for a “natural” narratology, we wish to demonstrate that it is in fact possible to think of “natural” narratology for music, which would consider every semiotic, semantic and narrative phenomenon found in the listening of music. We then open the question of the apparent difference between music experts’ and non-experts’ “narrativizations”.

  5. Une histoire de la physique moderne

    CERN Document Server

    Guillaud, Jean-Paul

    2010-01-01

    Vous étiez noyé dans les théorèmes et perdu dans vos cours de physique ? Et pourtant les informations sur les grands laboratoires de recherche explorant la matière vous intéressent et vous souhaiteriez en comprendre les enjeux ? Alors cet ouvrage de vulgarisation scientifique est pour vous. Ce livre dresse le plus simplement possible un panorama de la physique moderne en abordant : la relativité restreinte, la relativité générale, la physique quantique. Vous verrez : cette science n'est pas si hermétique et la profession de physicien est passionnante. La physique est au cœur de l'actualité avec la mise en service du nouvel accélérateur du CERN, le LHC, qui a fait la une de tous les médias. Ce livre prépare le lecteur à apprécier comme il se doit les découvertes à venir.

  6. Random matrix ensembles with column/row constraints: II

    International Nuclear Information System (INIS)

    We numerically analyze the random matrix ensembles of real-symmetric matrices with column/row constraints for many system conditions e.g. disorder type, matrix-size and basis-connectivity. The results reveal a rich behavior hidden beneath the spectral statistics and also confirm our analytical predictions, presented in part I of this paper, about the analogy of their spectral fluctuations with those of a critical Brownian ensemble which appears between Poisson and Gaussian orthogonal ensemble. (paper)

  7. Enhanced ensemble-based 4DVar scheme for data assimilation

    OpenAIRE

    Yang, Yin; Robinson, Cordelia; Heitz, Dominique; Mémin, Etienne

    2015-01-01

    International audience Ensemble based optimal control schemes combine the components of ensemble Kalman filters and variational data assimilation (4DVar). They are trendy because they are easier to implement than 4DVar. In this paper, we evaluate a modified version of an ensemble based optimal control strategy for image data assimilation. This modified method is assessed with a Shallow Water model combined with synthetic data and original incomplete experimental depth sensor observations. ...

  8. Data assimilation with the weighted ensemble Kalman filter

    OpenAIRE

    Papadakis, Nicolas; Mémin, Etienne; Cuzol, Anne; Gengembre, Nicolas

    2010-01-01

    In this paper, two data assimilation methods based on sequential Monte Carlo sampling are studied and compared: the ensemble Kalman filter and the particle filter. Each of these techniques has its own advantages and drawbacks. In this work, we try to get the best of each method by combining them. The proposed algorithm, called the weighted ensemble Kalman filter, consists to rely on the Ensemble Kalman Filter updates of samples in order to define a proposal distribution for the particle filte...

  9. Black Hole Statistical Mechanics and The Angular Velocity Ensemble

    OpenAIRE

    Thomson, Mitchell; Dyer, Charles C.

    2012-01-01

    An new ensemble - the angular velocity ensemble - is derived using Jaynes' method of maximising entropy subject to prior information constraints. The relevance of the ensemble to black holes is motivated by a discussion of external parameters in statistical mechanics and their absence from the Hamiltonian of general relativity. It is shown how this leads to difficulty in deriving entropy as a function of state and recovering the first law of thermodynamics from the microcanonical and canonica...

  10. Unconditional two-mode squeezing of separated atomic ensembles

    CERN Document Server

    Parkins, A S; Solano, E

    2005-01-01

    We propose schemes for the unconditional preparation of a two-mode squeezed state of effective bosonic modes realized in a pair of atomic ensembles interacting collectively with optical cavity and laser fields. The scheme uses Raman transitions between stable atomic ground states and under ideal conditions produces pure entangled states in the steady state. The scheme works both for ensembles confined within a single cavity and for ensembles confined in separate, cascaded cavities.

  11. Enhanced Sampling in the Well-Tempered Ensemble

    OpenAIRE

    Bonomi, M.; Parrinello, M

    2009-01-01

    We introduce the well-tempered ensemble (WTE) which is the biased ensemble sampled by well-tempered metadynamics when the energy is used as collective variable. WTE can be designed so as to have approximately the same average energy as the canonical ensemble but much larger fluctuations. These two properties lead to an extremely fast exploration of phase space. An even greater efficiency is obtained when WTE is combined with parallel tempering. Unbiased Boltzmann averages are computed on the ...

  12. Ecotourism certification and its progress in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Since the middle 1990s, ecotourism certification has been given more and more attention to around the world.As a developing country with abundant ecotourism products, it is necessaryfor China to adopt certification to ensure sustainable development of ecotourism. But there are few products certificated until now in China. After reviewing the trend of ecotourism certification in the world and summarizing its theory and method, this paper analyzes the progress and prospect of ecotourism certification in China, and concludes that certification in China is necessary and promising.

  13. Bayesian ensemble refinement by replica simulations and reweighting

    Science.gov (United States)

    Hummer, Gerhard; Köfinger, Jürgen

    2015-12-01

    We describe different Bayesian ensemble refinement methods, examine their interrelation, and discuss their practical application. With ensemble refinement, the properties of dynamic and partially disordered (bio)molecular structures can be characterized by integrating a wide range of experimental data, including measurements of ensemble-averaged observables. We start from a Bayesian formulation in which the posterior is a functional that ranks different configuration space distributions. By maximizing this posterior, we derive an optimal Bayesian ensemble distribution. For discrete configurations, this optimal distribution is identical to that obtained by the maximum entropy "ensemble refinement of SAXS" (EROS) formulation. Bayesian replica ensemble refinement enhances the sampling of relevant configurations by imposing restraints on averages of observables in coupled replica molecular dynamics simulations. We show that the strength of the restraints should scale linearly with the number of replicas to ensure convergence to the optimal Bayesian result in the limit of infinitely many replicas. In the "Bayesian inference of ensembles" method, we combine the replica and EROS approaches to accelerate the convergence. An adaptive algorithm can be used to sample directly from the optimal ensemble, without replicas. We discuss the incorporation of single-molecule measurements and dynamic observables such as relaxation parameters. The theoretical analysis of different Bayesian ensemble refinement approaches provides a basis for practical applications and a starting point for further investigations.

  14. Bayesian ensemble refinement by replica simulations and reweighting.

    Science.gov (United States)

    Hummer, Gerhard; Köfinger, Jürgen

    2015-12-28

    We describe different Bayesian ensemble refinement methods, examine their interrelation, and discuss their practical application. With ensemble refinement, the properties of dynamic and partially disordered (bio)molecular structures can be characterized by integrating a wide range of experimental data, including measurements of ensemble-averaged observables. We start from a Bayesian formulation in which the posterior is a functional that ranks different configuration space distributions. By maximizing this posterior, we derive an optimal Bayesian ensemble distribution. For discrete configurations, this optimal distribution is identical to that obtained by the maximum entropy "ensemble refinement of SAXS" (EROS) formulation. Bayesian replica ensemble refinement enhances the sampling of relevant configurations by imposing restraints on averages of observables in coupled replica molecular dynamics simulations. We show that the strength of the restraints should scale linearly with the number of replicas to ensure convergence to the optimal Bayesian result in the limit of infinitely many replicas. In the "Bayesian inference of ensembles" method, we combine the replica and EROS approaches to accelerate the convergence. An adaptive algorithm can be used to sample directly from the optimal ensemble, without replicas. We discuss the incorporation of single-molecule measurements and dynamic observables such as relaxation parameters. The theoretical analysis of different Bayesian ensemble refinement approaches provides a basis for practical applications and a starting point for further investigations.

  15. Fractional exclusion statistics and the Random Matrix Boson Ensemble

    CERN Document Server

    Hernández-Quiroz, Saul; Benet, Luis; Flores, Jorge; Cocho, Germinal

    2012-01-01

    The k-body Gaussian Embedded Ensemble of Random Matrices is considered for N bosons distributed on two single-particle levels. When k = N, the ensemble is equivalent to the Gaussian Orthogonal Ensemble (GOE), and when k = 2 it corresponds to the Two-body Random Ensemble (TBRE) for bosons. It is shown that the energy spectrum leads to a rank function which is of the form of a discrete generalized beta distribution. The same distribution is obtained assuming N non-interacting quasiparticles that obey the fractional exclusion statistics introduced by Haldane two decades ago.

  16. Relation between native ensembles and experimental structures of proteins

    DEFF Research Database (Denmark)

    Best, R. B.; Lindorff-Larsen, Kresten; DePristo, M. A.;

    2006-01-01

    Data Bank ensembles; moreover, we show that the effects of uncertainties in structure determination are insufficient to explain the results. These results highlight the importance of accounting for native-state protein dynamics in making comparisons with ensemble-averaged experimental data and suggest......Different experimental structures of the same protein or of proteins with high sequence similarity contain many small variations. Here we construct ensembles of "high-sequence similarity Protein Data Bank" (HSP) structures and consider the extent to which such ensembles represent the structural...

  17. Ensemble Kalman filtering with residual nudging

    Directory of Open Access Journals (Sweden)

    Xiaodong Luo

    2012-10-01

    Full Text Available Covariance inflation and localisation are two important techniques that are used to improve the performance of the ensemble Kalman filter (EnKF by (in effect adjusting the sample covariances of the estimates in the state space. In this work, an additional auxiliary technique, called residual nudging, is proposed to monitor and, if necessary, adjust the residual norms of state estimates in the observation space. In an EnKF with residual nudging, if the residual norm of an analysis is larger than a pre-specified value, then the analysis is replaced by a new one whose residual norm is no larger than a pre-specified value. Otherwise, the analysis is considered as a reasonable estimate and no change is made. A rule for choosing the pre-specified value is suggested. Based on this rule, the corresponding new state estimates are explicitly derived in case of linear observations. Numerical experiments in the 40-dimensional Lorenz 96 model show that introducing residual nudging to an EnKF may improve its accuracy and/or enhance its stability against filter divergence, especially in the small ensemble scenario.

  18. Hsaing Waing: Classical Ensemble of Myanmar

    Directory of Open Access Journals (Sweden)

    Chalermkit Kengkeaw

    2013-09-01

    Full Text Available Hsaing Waing is a classical music ensemble and a prominent culturalidentity of Myanmar. The Hsaing Waing ensemble consists of many instruments such as the Pat Waing, Muang Hsaing, Hne, Chauk Lon Bat, Byaung, Wa, Wallet Kok, Yakin, Si, and Mong. The earliest historical record of the Hsaing Waing is in 1544 where the Pat Waing and possibly the Hsaing Waing, was in royal service at the court of King Tabinshwehti of the Taungoo dynasty and prospered under the Kaunbaun dynasty up to colonial rule. During colonization, Hsaing Waing’s popularity declined but other innovations were introduced such as modern recording mediums and broadcasts which transferred the popularity of Hsaing Waing to a broader public audience and brought innovation to religious music, ceremonial rituals, fusion of westernmusical instruments such as the piano, violin and mandolin. The wealth of knowledge and numbers of connoisseur during the Kaunbaun dynasty led to the transfer of knowledge to many apprentices which were responsible for the development and adaptation and continuation of Hsaing Waing during colonization, socialism and independence. The transfer of knowledge was carried out by previous generations through apprentices, family members, close relatives and inspired individuals. The factors for the successful inheritance of Hsaing Waing are management, education, musicians and opportunity.

  19. Ensemble Kalman filtering with residual nudging

    KAUST Repository

    Luo, X.

    2012-10-03

    Covariance inflation and localisation are two important techniques that are used to improve the performance of the ensemble Kalman filter (EnKF) by (in effect) adjusting the sample covariances of the estimates in the state space. In this work, an additional auxiliary technique, called residual nudging, is proposed to monitor and, if necessary, adjust the residual norms of state estimates in the observation space. In an EnKF with residual nudging, if the residual norm of an analysis is larger than a pre-specified value, then the analysis is replaced by a new one whose residual norm is no larger than a pre-specified value. Otherwise, the analysis is considered as a reasonable estimate and no change is made. A rule for choosing the pre-specified value is suggested. Based on this rule, the corresponding new state estimates are explicitly derived in case of linear observations. Numerical experiments in the 40-dimensional Lorenz 96 model show that introducing residual nudging to an EnKF may improve its accuracy and/or enhance its stability against filter divergence, especially in the small ensemble scenario.

  20. Deterministic Mean-Field Ensemble Kalman Filtering

    KAUST Repository

    Law, Kody J. H.

    2016-05-03

    The proof of convergence of the standard ensemble Kalman filter (EnKF) from Le Gland, Monbet, and Tran [Large sample asymptotics for the ensemble Kalman filter, in The Oxford Handbook of Nonlinear Filtering, Oxford University Press, Oxford, UK, 2011, pp. 598--631] is extended to non-Gaussian state-space models. A density-based deterministic approximation of the mean-field limit EnKF (DMFEnKF) is proposed, consisting of a PDE solver and a quadrature rule. Given a certain minimal order of convergence k between the two, this extends to the deterministic filter approximation, which is therefore asymptotically superior to standard EnKF for dimension d<2k. The fidelity of approximation of the true distribution is also established using an extension of the total variation metric to random measures. This is limited by a Gaussian bias term arising from nonlinearity/non-Gaussianity of the model, which arises in both deterministic and standard EnKF. Numerical results support and extend the theory.

  1. Une science du langage pour une science de l'humain

    Directory of Open Access Journals (Sweden)

    Jean-Paul Bronckart

    2011-01-01

    Full Text Available L'auteur de cet article propose d'abord une analyse de l'évolution des sciences du langage au cours des dernières décennies, qui fait apparaître la difficulté d'identifier un cadre épistémologique susceptible de se substituer au défunt programme chomskyen. Il soutient ensuite que l'enjeu central des sciences sociales est de comprendre comment s'est constitué, et comment se développe, l'espace gnoséologique proprement humain, et il examine à ce propos les apports des courants du cognitivisme, du constructivisme (de Piaget et de l'interactionnisme social. L'auteur procède alors à une description détaillée de divers apports des sciences du langage: la conception saussurienne du statut des signes ainsi que les rapports entre textes et langues; la conception de Volochinov du rôle des discours dans le développement social; les approches de l'architecture des textes. Sur ces bases, il démontre enfin en quoi les sciences du langage peuvent fournir un appui décisif aux sciences de l'homme.

  2. Effect of Doubling the Ensemble Size on the Performance of Ensemble Prediction in the Warm Season Using MOGREPS Implemented at the KMA

    Institute of Scientific and Technical Information of China (English)

    Jun Kyung KAY; Hyun Mee KIM; Young-Youn PARK; Joohyung SON

    2013-01-01

    Using the Met Office Global and Regional Ensemble Prediction System (MOGREPS) implemented at the Korea Meteorological Administration (KMA),the effect of doubling the ensemble size on the performance of ensemble prediction in the warm season was evaluated.Because a finite ensemble size causes sampling error in the full forecast probability distribution function (PDF),ensemble size is closely related to the efficiency of the ensemble prediction system.Prediction capability according to doubling the ensemble size was evaluated by increasing the number of ensembles from 24 to 48 in MOGREPS implemented at the KMA.The initial analysis perturbations generated by the Ensemble Transform Kalman Filter (ETKF) were integrated for 10 days from 22 May to 23 June 2009.Several statistical verification scores were used to measure the accuracy,reliability,and resolution of ensemble probabilistic forecasts for 24 and 48 ensemble member forecasts.Even though the results were not significant,the accuracy of ensemble prediction improved slightly as ensemble size increased,especially for longer forecast times in the Northern Hemisphere.While increasing the number of ensemble members resulted in a slight improvement in resolution as forecast time increased,inconsistent results were obtained for the scores assessing the reliability of ensemble prediction.The overall performance of ensemble prediction in terms of accuracy,resolution,and reliability increased slightly with ensemble size,especially for longer forecast times.

  3. AutoCAD 2014 review for certification official certification preparation

    CERN Document Server

    ASCENT center for technical knowledge

    2014-01-01

    The AutoCAD® 2014 Review for Certification book is intended for users of AutoCAD® preparing to complete the AutoCAD 2014 Certified Professional exam. This book contains a collection of relevant instructional topics, practice exercises, and review questions from the Autodesk Official Training Guides (AOTG) from ASCENT - Center for Technical Knowledge pertaining specifically to the Certified Professional exam topics and objectives. This book is intended for experienced users of AutoCAD in preparation for certification. New users of AutoCAD should refer to the AOTG training guides from ASCENT, such as AutoCAD/AutoCAD LT 2014 Fundamentals, for more comprehensive instruction.

  4. Une pratique intertextuelle d'Aragon

    Directory of Open Access Journals (Sweden)

    Hervé Bismuth

    1999-09-01

    Full Text Available L'écriture du poème implique un « Je » susceptible d'impliquer à son tour un « tu » qui n'est pas seulement le lecteur. C'est dans cette particularité énonciative que s'inscrit la pratique du poème-hommage, qui, dans la poésie moderne, est prétexte à des jeux intertextuels. Dans le poème Les Poètes, Aragon complique la pratique coutumière de ce dialogue intertextuel, en plaçant le lecteur dans la perspective d'une intertextualité infinie, stratégie qui peut se décrire par l'étude de trois pratiques nouvelles alors chez Aragon : la mise en icône, le jeu de piste et ce que j'appellerai l'intertextualité tierce. Dans ce poème dont le scripteur ne cesse de parler à la première personne, s'impose à travers ces trois pratiques, qui coexistent avec d'autres, bien plus traditionnelles, la perspective d'une intertextualité abyssale.Writing a poem implies the existence of the « I », who is likely to involve another « you » who is not only the reader. Within the framework of this particular enunciation lies the use of the homage-poem which provides modern poetry with a pretext for intertextual play. In the poem Les poètes, Aragon heightens the complexity of the usual intertextual dialogue, putting the reader in the perspective of infinite intertextuality. This strategy can be described by the study of three new practices in Aragon's work – icon-making, track games, and what I would call the third intertextuality. In this first-person poem, the perspective of abysmal intertextuality prevails through these three practices coexisting with other more traditional ones.La escritura del poema implica un « yo » susceptible de implicar a su vez un « tú » que no es únicamente el lector. Es dentro de esta particularidad enunciativa donde se sitúa la práctica del poema-homenaje, que, en la poesia moderna, sirve de pretexto a varios juegos intertextuales. En el poema Les Poètes, Aragon complica la pr

  5. Une terreur par l’image

    Directory of Open Access Journals (Sweden)

    Annie DULONG

    2011-09-01

    Full Text Available Si d’autres événements — Hiroshima, la découverte des camps de concentration, la chute du mur de Berlin — ont, au cours du XXe siècle, marqué suffisamment l’imaginaire pour trouver leur réponse dans des œuvres d’art, le 11 septembre 2001 pose la question de la fictionnalisation autrement : il ne s’agit plus tant de combler les manques de la représentation, liés à l’absence d’images ou au délai dans leur dévoilement, mais bien de composer avec l’omniprésence d’une représentation martelée à la télévision et sur Internet. Que cette représentation soit partielle, tronquée et qu’il lui manque la présence des corps, ces grands absents des photographies et des images tournées par les journalistes, ne change rien au fait que c’est avec le trop-plein que les artistes doivent maintenant négocier.Cet article s’intéresse aux romans qui traitent l’événement de front au lieu de l’aborder sur un mode mineur, et a pour objectif de tracer un portrait de la représentation des médias dans les romans du 11 septembre 2001. Ces romans, outre le fait qu’ils traitent des événements de New York, ont comme point commun un personnage, ou décor : les médias, représentés par la télévision, l’Internet, les photographies de presse, interviennent dans les récits d’une manière significative et témoignent de la force brute des images. À travers une étude de certains des mécanismes à l’œuvre dans The Writing on the Wall (Lynne Sharon Schwartz, Extremely Loud and Incredibly Close (Jonathan Safran Foer, Falling Man (Don DeLillo et A Disorder Peculiar to the Country (Ken Kalfus, il s’agira de proposer des réponses à ces quelques questions : quel rôle les médias jouent-ils, et comment participent-ils au récit ? Quelle pression les images exercent-elles sur les personnages ? Que révèlent les personnages enfants dans leur rapport aux médias ? Quelle critique, finalement, les romans

  6. 7 CFR 205.404 - Granting certification.

    Science.gov (United States)

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Certification § 205.404 Granting certification. (a) Within a...

  7. 33 CFR 274.5 - Certification.

    Science.gov (United States)

    2010-07-01

    ... PEST CONTROL PROGRAM FOR CIVIL WORKS PROJECTS Project Operation § 274.5 Certification. Under the... certification of Civil Works personnel. Pending final approval of the DOD Agency Plan, all Corps of Engineers... and the Division Engineer....

  8. Quality certificates for homeopathic matrices

    Directory of Open Access Journals (Sweden)

    Amarilys de Toledo Cesar

    2011-09-01

    Full Text Available Background: To produce homeopathic medicines, pharmacies need raw materials (mother tinctures and diluted-agitated solutions, named “matrices”, provided by insumes suppliers. The “matrices” are ultra high dilutions and can not be tested against Analysis Reports. Aims: to propose alternatives to the matrices Analysis Report; to contribute to the quality of homeopathic medicines and treatment. Method: search of information present in the documentation provided from 2 national and 3 European suppliers in order to develop criteria. Discussion: the needed concepts for compliance with the orders throughout their production process were presented. The control of information involved in the process allows to trace the production of matrices, providing an indication of the quality with which they were obtained. Each supplier gives different approach to issuing a document, calling it Certificate of Conformity Protocol Preparation, Manufacturing Certificate or Quality Certificate. Summarizing, it is a supplier's declaration, which involves the quality control of raw materials, packaging materials and of the process used, but not a report that enables customers to repeat the analysis. A model was proposed for a Certificate of Quality, with the minimum information needed to indicate to the pharmacies that there is a control of the process. This certificate shall contain statements about the process. Conclusion: Quality Certificate seems to be the best document to ensure the pharmacy that the matrix obtained presents characteristics compatible with the preparation of a quality homeopathic medicine.

  9. Certificate Transparency in Theory and Practice

    OpenAIRE

    Gustafsson, Josef

    2016-01-01

    Certificate Transparency provides auditability to the widely used X.509 Public Key Infrastructure (PKIX) authentication in Transport Layer Security (TLS) protocol. Transparency logs issue signed promises of inclusions to be used together with certificates for authentication of TLS servers. Google Chrome enforces the use of Certificate Transparency for validation of Extended Validation (EV) certificates. This thesis proposes a methodology for asserting correct operation and presents a survey o...

  10. Certification of ICTs in Elections

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Barrat, Jordi; Bolo, Eden;

    2015-01-01

    Information and communication technologies play a critical role in the administration and organization of modern elections. Any breakdown of an election technology, security breach or programming error can incur tremendous cost for the electoral management body (EMB)—and may undermine voters’ trust...... voting or tabulation systems. The key elements of quality control are certification and evaluation. Certification refers to the confirmation proof of compliance with a given standard. Evaluation is the most labour intensive part of the quality control process during which the requirements, designs...

  11. Open source systems security certification

    CERN Document Server

    Damiani, Ernesto; El Ioini, Nabil

    2009-01-01

    Open Source Advances in Computer Applications book series provides timely technological and business information for: Enabling Open Source Systems (OSS) to become an integral part of systems and devices produced by technology companies; Inserting OSS in the critical path of complex network development and embedded products, including methodologies and tools for domain-specific OSS testing (lab code available), plus certification of security, dependability and safety properties for complex systems; Ensuring integrated systems, including OSS, meet performance and security requirements as well as achieving the necessary certifications, according to the overall strategy of OSS usage on the part of the adopter

  12. Ensemble Forecast: A New Approach to Uncertainty and Predictability

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Ensemble techniques have been used to generate daily numerical weather forecasts since the 1990s in numerical centers around the world due to the increase in computation ability. One of the main purposes of numerical ensemble forecasts is to try to assimilate the initial uncertainty (initial error) and the forecast uncertainty (forecast error) by applying either the initial perturbation method or the multi-model/multiphysics method. In fact, the mean of an ensemble forecast offers a better forecast than a deterministic (or control) forecast after a short lead time (3 5 days) for global modelling applications. There is about a 1-2-day improvement in the forecast skill when using an ensemble mean instead of a single forecast for longer lead-time. The skillful forecast (65% and above of an anomaly correlation) could be extended to 8 days (or longer) by present-day ensemble forecast systems. Furthermore, ensemble forecasts can deliver a probabilistic forecast to the users, which is based on the probability density function (PDF)instead of a single-value forecast from a traditional deterministic system. It has long been recognized that the ensemble forecast not only improves our weather forecast predictability but also offers a remarkable forecast for the future uncertainty, such as the relative measure of predictability (RMOP) and probabilistic quantitative precipitation forecast (PQPF). Not surprisingly, the success of the ensemble forecast and its wide application greatly increase the confidence of model developers and research communities.

  13. Modality-Driven Classification and Visualization of Ensemble Variance

    Energy Technology Data Exchange (ETDEWEB)

    Bensema, Kevin; Gosink, Luke J.; Obermaier, Harald; Joy, Kenneth

    2016-10-01

    Advances in computational power now enable domain scientists to address conceptual and parametric uncertainty by running simulations multiple times in order to sufficiently sample the uncertain input space. While this approach helps address conceptual and parametric uncertainties, the ensemble datasets produced by this technique present a special challenge to visualization researchers as the ensemble dataset records a distribution of possible values for each location in the domain. Contemporary visualization approaches that rely solely on summary statistics (e.g., mean and variance) cannot convey the detailed information encoded in ensemble distributions that are paramount to ensemble analysis; summary statistics provide no information about modality classification and modality persistence. To address this problem, we propose a novel technique that classifies high-variance locations based on the modality of the distribution of ensemble predictions. Additionally, we develop a set of confidence metrics to inform the end-user of the quality of fit between the distribution at a given location and its assigned class. We apply a similar method to time-varying ensembles to illustrate the relationship between peak variance and bimodal or multimodal behavior. These classification schemes enable a deeper understanding of the behavior of the ensemble members by distinguishing between distributions that can be described by a single tendency and distributions which reflect divergent trends in the ensemble.

  14. Practice Makes Perfect?: Effective Practice Instruction in Large Ensembles

    Science.gov (United States)

    Prichard, Stephanie

    2012-01-01

    Helping young musicians learn how to practice effectively is a challenge faced by all music educators. This article presents a system of individual music practice instruction that can be seamlessly integrated within large-ensemble rehearsals. Using a step-by-step approach, large-ensemble conductors can teach students to identify and isolate…

  15. An iterative ensemble Kalman filter for reservoir engineering applications

    NARCIS (Netherlands)

    Krymskaya, M.V.; Hanea, R.G.; Verlaan, M.

    2009-01-01

    The study has been focused on examining the usage and the applicability of ensemble Kalman filtering techniques to the history matching procedures. The ensemble Kalman filter (EnKF) is often applied nowadays to solving such a problem. Meanwhile, traditional EnKF requires assumption of the distributi

  16. Exact ensemble density-functional theory for excited states

    CERN Document Server

    Yang, Zeng-hui; Pribram-Jones, Aurora; Burke, Kieron; Needs, Richard J; Ullrich, Carsten A

    2014-01-01

    We construct exact Kohn-Sham potentials for the ensemble density-functional theory (EDFT) of excited states from the ground and excited states of helium. The exchange-correlation potential is compared with current approximations, which miss prominent features. The ensemble derivative discontinuity is tested, and the virial theorem is proven and illustrated.

  17. A Comparison of Ensemble Kalman Filters for Storm Surge Assimilation

    KAUST Repository

    Altaf, M. U.

    2014-08-01

    This study evaluates and compares the performances of several variants of the popular ensembleKalman filter for the assimilation of storm surge data with the advanced circulation (ADCIRC) model. Using meteorological data from Hurricane Ike to force the ADCIRC model on a domain including the Gulf ofMexico coastline, the authors implement and compare the standard stochastic ensembleKalman filter (EnKF) and three deterministic square root EnKFs: the singular evolutive interpolated Kalman (SEIK) filter, the ensemble transform Kalman filter (ETKF), and the ensemble adjustment Kalman filter (EAKF). Covariance inflation and localization are implemented in all of these filters. The results from twin experiments suggest that the square root ensemble filters could lead to very comparable performances with appropriate tuning of inflation and localization, suggesting that practical implementation details are at least as important as the choice of the square root ensemble filter itself. These filters also perform reasonably well with a relatively small ensemble size, whereas the stochastic EnKF requires larger ensemble sizes to provide similar accuracy for forecasts of storm surge.

  18. Competitive Learning Neural Network Ensemble Weighted by Predicted Performance

    Science.gov (United States)

    Ye, Qiang

    2010-01-01

    Ensemble approaches have been shown to enhance classification by combining the outputs from a set of voting classifiers. Diversity in error patterns among base classifiers promotes ensemble performance. Multi-task learning is an important characteristic for Neural Network classifiers. Introducing a secondary output unit that receives different…

  19. Improving land resource evaluation using fuzzy neural network ensembles

    Science.gov (United States)

    XUE, Y.-J.; HU, Y.-M.; Liu, S.-G.; YANG, J.-F.; CHEN, Q.-C.; BAO, S.-T.

    2007-01-01

    Land evaluation factors often contain continuous-, discrete- and nominal-valued attributes. In traditional land evaluation, these different attributes are usually graded into categorical indexes by land resource experts, and the evaluation results rely heavily on experts' experiences. In order to overcome the shortcoming, we presented a fuzzy neural network ensemble method that did not require grading the evaluation factors into categorical indexes and could evaluate land resources by using the three kinds of attribute values directly. A fuzzy back propagation neural network (BPNN), a fuzzy radial basis function neural network (RBFNN), a fuzzy BPNN ensemble, and a fuzzy RBFNN ensemble were used to evaluate the land resources in Guangdong Province. The evaluation results by using the fuzzy BPNN ensemble and the fuzzy RBFNN ensemble were much better than those by using the single fuzzy BPNN and the single fuzzy RBFNN, and the error rate of the single fuzzy RBFNN or fuzzy RBFNN ensemble was lower than that of the single fuzzy BPNN or fuzzy BPNN ensemble, respectively. By using the fuzzy neural network ensembles, the validity of land resource evaluation was improved and reliance on land evaluators' experiences was considerably reduced. ?? 2007 Soil Science Society of China.

  20. Ensembles and their modules as objects of cartosemiotic inquiry

    Directory of Open Access Journals (Sweden)

    Hansgeorg Schlichtmann

    2010-01-01

    Full Text Available The structured set of signs in a map face -- here called map-face aggregate or MFA -- and the associated marginal notes make up an ensemble of modules or components (modular ensemble. Such ensembles are recognized where groups of entries are intuitively viewed as complex units, which includes the case that entries are consulted jointly and thus are involved in the same process of sign reception. Modular ensembles are amenable to semiotic study, just as are written or pictorial stories. Four kinds (one of them mentioned above are discussed in detail, two involving single MFAs, the other two being assemblages of maps, such as atlases. In terms of their internal structure, two types are recognized: the combinate (or grouping, in which modules are directly linked by combinatorial relations (example above, and the cumulate (or collection (of documents, in which modules are indirectly related through some conceptual commonality (example: series of geological maps. The discussion then turns to basic points concerning modular ensembles (identification of a module, internal organization of an ensemble, and characteristics which establish an ensemble as a unit and further to a few general semiotic concepts as they relate to the present research. Since this paper originated as a reaction to several of A. Wolodtschenko’s recent publications, it concludes with comments on some of his arguments which pertain to modular ensembles.

  1. Thermal Insulation Distribution Pattern of Layered Clothing Ensemble

    Institute of Scientific and Technical Information of China (English)

    李俊; 韦鸿发; 刘岩; 张渭源

    2004-01-01

    With a thermal manikin, the distribution pattern of thermal insulation in multi-layered clothing ensemble is studied. It is found that the thermal insulation of multi-layered clothing ensemble has certain statistical relationship with the thermal insulation of each layer, and the prediction equation has been established.

  2. Effect of lateral boundary perturbations on the breeding method and the local ensemble transform Kalman filter for mesoscale ensemble prediction

    Directory of Open Access Journals (Sweden)

    Kazuo Saito

    2012-01-01

    Full Text Available The effect of lateral boundary perturbations (LBPs on the mesoscale breeding (MBD method and the local ensemble transform Kalman filter (LETKF as the initial perturbations generators for mesoscale ensemble prediction systems (EPSs was examined. A LBPs method using the Japan Meteorological Agency's (JMA's operational one-week global ensemble prediction was developed and applied to the mesoscale EPS of the Meteorological Research Institute for the World Weather Research Programme, Beijing 2008 Olympics Research and Development Project. The amplitude of the LBPs was adjusted based on the ensemble spread statistics considering the difference of the forecast times of the JMA's one-week EPS and the associated breeding/ensemble Kalman filter (EnKF cycles. LBPs in the ensemble forecast increase the ensemble spread and improve the accuracy of the ensemble mean forecast. In the MBD method, if LBPs were introduced in its breeding cycles, the growth rate of the generated bred vectors is increased, and the ensemble spread and the root mean square errors (RMSEs of the ensemble mean are further improved in the ensemble forecast. With LBPs in the breeding cycles, positional correspondences to the meteorological disturbances and the orthogonality of the bred vectors are improved. Brier Skill Scores (BSSs also showed a remarkable effect of LBPs in the breeding cycles. LBPs showed a similar effect with the LETKF. If LBPs were introduced in the EnKF data assimilation cycles, the ensemble spread, ensemble mean accuracy, and BSSs for precipitation were improved, although the relative advantage of LETKF as the initial perturbations generator against MDB was not necessarily clear. LBPs in the EnKF cycles contribute not to the orthogonalisation but to prevent the underestimation of the forecast error near the lateral boundary.The accuracy of the LETKF analyses was compared with that of the mesoscale 4D-VAR analyses. With LBPs in the LETKF cycles, the RMSEs of the

  3. La conscience environnementale, condition d’une puissance soutenable ?

    Directory of Open Access Journals (Sweden)

    François Gemenne

    2013-01-01

    Full Text Available Cette contribution ambitionne de montrer en quoi les crises environnementales représentent une menace pour la stabilité des Etats, et donc un élément de leur affaiblissement. L'article met ainsi en évidence la corrélation entre les dégradations – brutales ou graduelles – de l’environnement et les problèmes de sécurité intérieure, ainsi que les processus sous-jacents à cette corrélation. Dans une seconde partie, l'article examine, a contrario, en quoi le développement durable peut constituer la condition d’une puissance soutenable. Puissance diplomatique d’abord, avec le développement considérable des questions environnementales dans les relations internationales, notamment autour d’enjeux mondiaux comme le changement climatique. Puissance économique ensuite, à l’heure où beaucoup d’économistes érigent la croissance verte en modèle d’une nouvelle prospérité pour les pays industrialisés, et la considèrent comme une voie de développement porteuse pour les pays du Sud.

  4. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  5. Predicting protein dynamics from structural ensembles

    CERN Document Server

    Copperman, J

    2015-01-01

    The biological properties of proteins are uniquely determined by their structure and dynamics. A protein in solution populates a structural ensemble of metastable configurations around the global fold. From overall rotation to local fluctuations, the dynamics of proteins can cover several orders of magnitude in time scales. We propose a simulation-free coarse-grained approach which utilizes knowledge of the important metastable folded states of the protein to predict the protein dynamics. This approach is based upon the Langevin Equation for Protein Dynamics (LE4PD), a Langevin formalism in the coordinates of the protein backbone. The linear modes of this Langevin formalism organize the fluctuations of the protein, so that more extended dynamical cooperativity relates to increasing energy barriers to mode diffusion. The accuracy of the LE4PD is verified by analyzing the predicted dynamics across a set of seven different proteins for which both relaxation data and NMR solution structures are available. Using e...

  6. Optimal Spatial Prediction Using Ensemble Machine Learning.

    Science.gov (United States)

    Davies, Molly Margaret; van der Laan, Mark J

    2016-05-01

    Spatial prediction is an important problem in many scientific disciplines. Super Learner is an ensemble prediction approach related to stacked generalization that uses cross-validation to search for the optimal predictor amongst all convex combinations of a heterogeneous candidate set. It has been applied to non-spatial data, where theoretical results demonstrate it will perform asymptotically at least as well as the best candidate under consideration. We review these optimality properties and discuss the assumptions required in order for them to hold for spatial prediction problems. We present results of a simulation study confirming Super Learner works well in practice under a variety of sample sizes, sampling designs, and data-generating functions. We also apply Super Learner to a real world dataset. PMID:27130244

  7. Modeling Coordination Problems in a Music Ensemble

    DEFF Research Database (Denmark)

    Frimodt-Møller, Søren R.

    2008-01-01

    This paper considers in general terms, how musicians are able to coordinate through rational choices in a situation of (temporary) doubt in an ensemble performance. A fictitious example involving a 5-bar development in an unknown piece of music is analyzed in terms of epistemic logic, more...... specifically a multi-agent system, where it is shown that perfect coordination can only be certain to take place if the musicians have common knowledge of certain rules of the composition. We subsequently argue, however, that the musicians need not agree on the central features of the piece of music in order...... to coordinate. Such coordination can be described in terms of Michael Bacharach's theory of variable frames as an aid to solve game theoretic coordination problems....

  8. 28 CFR 26.23 - Certification process.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Certification process. 26.23 Section 26.23 Judicial Administration DEPARTMENT OF JUSTICE DEATH SENTENCES PROCEDURES Certification Process for State Capital Counsel Systems § 26.23 Certification process. (a) An appropriate state official...

  9. 14 CFR 147.3 - Certificate required.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Certificate required. 147.3 Section 147.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES AVIATION MAINTENANCE TECHNICIAN SCHOOLS General § 147.3 Certificate...

  10. 40 CFR 86.1848-01 - Certification.

    Science.gov (United States)

    2010-07-01

    ... Complete Otto-Cycle Heavy-Duty Vehicles § 86.1848-01 Certification. (a)(1) If, after a review of the... new motor vehicle covered by the certificate will meet the requirements of the Act and of this part... trucks and incomplete heavy-duty vehicles, a certificate covers only those new motor vehicles which,...

  11. 26 CFR 1.43-3 - Certification

    Science.gov (United States)

    2010-04-01

    ... § 1.43-3 Certification (a) Petroleum engineer's certification of a project—(1) In general. A petroleum... requirements of section 43(c)(2)(A). A petroleum engineer's certification must be submitted for each project. The petroleum engineer certifying a project must be duly registered or certified in any State....

  12. 14 CFR 21.275 - Experimental certificates.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Experimental certificates. 21.275 Section 21.275 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... certificates. (a) The manufacturer shall, before issuing an experimental certificate, obtain from...

  13. Emergence of overlap in ensembles of spatial multiplexes and statistical mechanics of spatial interacting networks ensembles

    CERN Document Server

    Halu, Arda; Bianconi, Ginestra

    2013-01-01

    Spatial networks range from the brain networks, to transportation networks and infrastructures. Recently interacting and multiplex networks are attracting great attention because their dynamics and robustness cannot be understood without treating at the same time several networks. Here we present maximal entropy ensembles of spatial multiplex and spatial interacting networks that can be used in order to model spatial multilayer network structures and to build null models of real datasets. We show that spatial multiplex naturally develop a significant overlap of the links, a noticeable property of many multiplexes that can affect significantly the dynamics taking place on them. Additionally, we characterize ensembles of spatial interacting networks and we analyse the structure of interacting airport and railway networks in India, showing the effect of space in determining the link probability.

  14. An educational model for ensemble streamflow simulation and uncertainty analysis

    Directory of Open Access Journals (Sweden)

    A. AghaKouchak

    2013-02-01

    Full Text Available This paper presents the hands-on modeling toolbox, HBV-Ensemble, designed as a complement to theoretical hydrology lectures, to teach hydrological processes and their uncertainties. The HBV-Ensemble can be used for in-class lab practices and homework assignments, and assessment of students' understanding of hydrological processes. Using this modeling toolbox, students can gain more insights into how hydrological processes (e.g., precipitation, snowmelt and snow accumulation, soil moisture, evapotranspiration and runoff generation are interconnected. The educational toolbox includes a MATLAB Graphical User Interface (GUI and an ensemble simulation scheme that can be used for teaching uncertainty analysis, parameter estimation, ensemble simulation and model sensitivity. HBV-Ensemble was administered in a class for both in-class instruction and a final project, and students submitted their feedback about the toolbox. The results indicate that this educational software had a positive impact on students understanding and knowledge of uncertainty in hydrological modeling.

  15. Ensemble-based Probabilistic Forecasting at Horns Rev

    DEFF Research Database (Denmark)

    Pinson, Pierre; Madsen, Henrik

    2009-01-01

    of probabilistic forecasts, the resolution of which may be maximized by using meteorological ensemble predictions as input. The paper concentrates on the test case of the Horns Rev wind form over a period of approximately 1 year, in order to describe, apply and discuss a complete ensemble-based probabilistic...... forecasting methodology. In a first stage, ensemble forecasts of meteorological variables are converted to power through a suitable power curve model. This modelemploys local polynomial regression, and is adoptively estimated with an orthogonal fitting method. The obtained ensemble forecasts of wind power...... the benefit of yielding predictive distributions that are of increased reliability (in a probabilistic sense) in comparison with the raw ensemble forecasts, at the some time taking advantage of their high resolution. Copyright (C) 2008 John Wiley & Sons, Ltd....

  16. Induced Ginibre ensemble of random matrices and quantum operations

    CERN Document Server

    Fischmann, J; Khoruzhenko, B A; Sommers, H -J; Zyczkowski, K

    2011-01-01

    A generalisation of the Ginibre ensemble of non-Hermitian random square matrices is introduced. The corresponding probability measure is induced by the ensemble of rectangular Gaussian matrices via a quadratisation procedure. We derive the joint probability density of eigenvalues for such induced Ginibre ensemble and study various spectral correlation functions for complex and real matrices, and analyse universal behaviour in the limit of large dimensions. In this limit the eigenvalues of the induced Ginibre ensemble cover uniformly a ring in the complex plane. The real induced Ginibre ensemble is shown to be useful to describe statistical properties of evolution operators associated with random quantum operations, for which the dimensions of the input state and the output state do differ.

  17. Excitations and benchmark ensemble density functional theory for two electrons

    CERN Document Server

    Pribram-Jones, Aurora; Trail, John R; Burke, Kieron; Needs, Richard J; Ullrich, Carsten A

    2014-01-01

    A new method for extracting ensemble Kohn-Sham potentials from accurate excited state densities is applied to a variety of two electron systems, exploring the behavior of exact ensemble density functional theory. The issue of separating the Hartree energy and the choice of degenerate eigenstates is explored. A new approximation, spin eigenstate Hartree-exchange (SEHX), is derived. Exact conditions that are proven include the signs of the correlation energy components, the virial theorem for both exchange and correlation, and the asymptotic behavior of the potential for small weights of the excited states. Many energy components are given as a function of the weights for two electrons in a one-dimensional flat box, in a box with a large barrier to create charge transfer excitations, in a three-dimensional harmonic well (Hooke's atom), and for the He atom singlet-triplet ensemble, singlet-triplet-singlet ensemble, and triplet bi-ensemble.

  18. Les Archives d’anthropologie criminelle : une revue pour une science

    Directory of Open Access Journals (Sweden)

    Marc Renneville

    2005-01-01

    Full Text Available « Ce sont des archives dans lesquelles sont longuement enregistrées les observations scientifiques, les affaires judiciaires, les modifications de la législation criminelle dans tous les pays. On peut dire, sans crainte d’exagération, que l’on trouvera dans les Archives un écho de toutes les affaires retentissantes qui se sont déroulées pendant ce quart de siècle. C’est là une mine de documents considérable pour les chercheurs de l’avenir ». Etienne Martin, Préface à la 25e année. Archives d’...

  19. Ensemble Bayesian forecasting system Part I: Theory and algorithms

    Science.gov (United States)

    Herr, Henry D.; Krzysztofowicz, Roman

    2015-05-01

    The ensemble Bayesian forecasting system (EBFS), whose theory was published in 2001, is developed for the purpose of quantifying the total uncertainty about a discrete-time, continuous-state, non-stationary stochastic process such as a time series of stages, discharges, or volumes at a river gauge. The EBFS is built of three components: an input ensemble forecaster (IEF), which simulates the uncertainty associated with random inputs; a deterministic hydrologic model (of any complexity), which simulates physical processes within a river basin; and a hydrologic uncertainty processor (HUP), which simulates the hydrologic uncertainty (an aggregate of all uncertainties except input). It works as a Monte Carlo simulator: an ensemble of time series of inputs (e.g., precipitation amounts) generated by the IEF is transformed deterministically through a hydrologic model into an ensemble of time series of outputs, which is next transformed stochastically by the HUP into an ensemble of time series of predictands (e.g., river stages). Previous research indicated that in order to attain an acceptable sampling error, the ensemble size must be on the order of hundreds (for probabilistic river stage forecasts and probabilistic flood forecasts) or even thousands (for probabilistic stage transition forecasts). The computing time needed to run the hydrologic model this many times renders the straightforward simulations operationally infeasible. This motivates the development of the ensemble Bayesian forecasting system with randomization (EBFSR), which takes full advantage of the analytic meta-Gaussian HUP and generates multiple ensemble members after each run of the hydrologic model; this auxiliary randomization reduces the required size of the meteorological input ensemble and makes it operationally feasible to generate a Bayesian ensemble forecast of large size. Such a forecast quantifies the total uncertainty, is well calibrated against the prior (climatic) distribution of

  20. Path ensembles for conformational transitions in adenylate kinase using weighted--ensemble path sampling

    CERN Document Server

    Bhatt, Divesh

    2009-01-01

    We perform first path sampling simulations of conformational transitions of semi--atomistic protein models. We generate an ensemble of pathways for conformational transitions between open and closed forms of adenylate kinase using weighted ensemble path sampling method. Such an ensemble of pathways is critical in determining the important regions of configuration space sampled during a transition. To different semi--atomistic models are used: one is a pure Go model, whereas the other includes level of residue specificity via use of Miyajawa--Jernigan type interactions and hydrogen bonding. For both the models, we find that the open form of adenylate kinase is more flexible and the the transition from open to close is significantly faster than the reverse transition. We find that the transition occurs via the AMP binding domain snapping shut at a fairly fast time scale. On the other hand, the flexible lid domain fluctuates significantly and the shutting of the AMP binding domain does not depend upon the positi...

  1. Robust Ensemble Filtering and Its Relation to Covariance Inflation in the Ensemble Kalman Filter

    KAUST Repository

    Luo, Xiaodong

    2011-12-01

    A robust ensemble filtering scheme based on the H∞ filtering theory is proposed. The optimal H∞ filter is derived by minimizing the supremum (or maximum) of a predefined cost function, a criterion different from the minimum variance used in the Kalman filter. By design, the H∞ filter is more robust than the Kalman filter, in the sense that the estimation error in the H∞ filter in general has a finite growth rate with respect to the uncertainties in assimilation, except for a special case that corresponds to the Kalman filter. The original form of the H∞ filter contains global constraints in time, which may be inconvenient for sequential data assimilation problems. Therefore a variant is introduced that solves some time-local constraints instead, and hence it is called the time-local H∞ filter (TLHF). By analogy to the ensemble Kalman filter (EnKF), the concept of ensemble time-local H∞ filter (EnTLHF) is also proposed. The general form of the EnTLHF is outlined, and some of its special cases are discussed. In particular, it is shown that an EnKF with certain covariance inflation is essentially an EnTLHF. In this sense, the EnTLHF provides a general framework for conducting covariance inflation in the EnKF-based methods. Some numerical examples are used to assess the relative robustness of the TLHF–EnTLHF in comparison with the corresponding KF–EnKF method.

  2. Le pouvoir d’une reine

    Directory of Open Access Journals (Sweden)

    Charles Garcia

    2006-08-01

    Full Text Available Les Chroniques anonymes de Sahagún rapportent les événements survenus dans cette ville au début du règne d’Urraque Ire de León-Castille. Or, curieusement, cette souveraine occupe une place relativement effacée dans la narration, bien qu’elle soit souvent dépeinte sous un jour favorable. Il faut dire que la reine, qui suivit la politique que son père avait engagée, fut d’un soutien constant pour les moines. Dans la Crónica, la vision positive d’Urraque, en tant que femme au pouvoir, contraste avec l’image que donnent d’elle les chroniques post-alphonsines. C’est donc à partir du croisement de ces sources, mais aussi d’autres documents, que nous tenterons de recomposer la place de cette femme à la tête du royaume et que nous essaierons de percer l’intention de l’image que donne l’auteur anonyme d’un récit bâti dans un but d’édification.Las Crónicas anónimas de Sahagún cuentan los acontecimientos que acaecieron en dicha ciudad en los primeros años del reinado de Urraca I de León-Castilla. No deja de extrañar que la reina no sea la principal protagonista del relato, aunque suela salir bien parada en él. Bien es verdad que la soberana no hizo sino proseguir una política favorable para con los benedictinos de Domnos Sanctos, una línea que ya había iniciado su padre. En la Crónica anónima la imagen positiva de Urraca, como mujer que ha conseguido izarse hasta el poder, contrasta con la percepción que de ella nos presentan las crónicas post-alfonsíes. Cruzando pues dichas fuentes, con otros más documentos, intentaremos acercarnos al papel que esta mujer desempeñó al frente del reino, así como al retrato que de ella hace el cronista anónimo en un relato que escribió con clara intención ejemplificadora.

  3. La syphilis congenitale revelee par une fracture spontanee

    Directory of Open Access Journals (Sweden)

    Mounia Lakhdar Idrissi

    2011-11-01

    Full Text Available Alors qu�elle est actuellement oubliee dans les pays developpes, la syphilis congenitale se voit encore chez nous faute du depistage antenatal. Ses formes cliniques sont polymorphes et orientent a tord vers d�autres pathologies surtout en periode neonatale. Le diagnostic n�est donc pas toujours facile. La revelation d�une syphilis congenitale par une fracture spontanee est exceptionnellement decrite. Nous rapportons dans ce travail le cas d�un nourrisson de 2 mois ramene en consultation pour limitation douloureuse des mouvements du bras droit. Le diagnostic est evoque sur les donnees radiologiques et confirme par la serologie syphilitique. Le traitement a repose essentiellement sur l�administration de la penicilline G avec une bonne evolution clinique.

  4. Trusted Certificates in Quantum Cryptography

    OpenAIRE

    Perkins, William

    2006-01-01

    This paper analyzes the performance of Kak's three stage quantum cryptographic protocol based on public key cryptography against a man-in-the-middle attack. A method for protecting against such an attack is presented using certificates distributed by a trusted third party.

  5. Teacher Certification/Preparation Guidelines.

    Science.gov (United States)

    Kotter, Rita

    1990-01-01

    Presents guidelines for general and theater specialist K-12 teacher certification developed by the American Alliance for Theatre Education and the Speech Communication Association. Advocates that all teachers have preparation in arts and communication and that theater and communication specialists continue to be trained. (SR)

  6. Esquisse d'une économie politique des affects

    OpenAIRE

    Citton, Yves

    2008-01-01

    Comment concevoir l'économie politique des affects qui régit nos sociétés d'abondance, à l'intersection de la neurobiologie, de la psychologie, de la psychanalyse, de la sociologie, de la médiologie, du marketing, des " relations publiques " et de l'activisme politique ? Comment en faire autre chose qu'une référence utile, mais assez vide, d'un certain discours philosophique contemporain ? Sur quelles bases esquisser une cartographie générale des dynamiques et des conditionnements censés rele...

  7. Chapitre 8. Une campagne en crise : mutations des terroirs wolaita

    OpenAIRE

    Planel, Sabine

    2013-01-01

    Le constat d’une crise des campagnes wolaita ne se formule pas avec simplicité. Si plusieurs facteurs – retard des précipitations, brusque augmentation des mortalités humaine et animale, disette – abondent en ce sens, ils demeurent difficiles à mesurer et leur existence même ne condamne pas nécessairement la survie des espaces ruraux. Il convient de savoir dans quelle mesure les systèmes agricoles entrent en crise ou peuvent supporter une charge démographique grandissante. L’orientation large...

  8. La focalisation contrastive en italien: une etude de cas

    OpenAIRE

    Augendre, Sandra

    2009-01-01

    L’article a pour but de travailler sur les stratégies pertinentes en italien afin de transmettre une information de type contrastif (focus contrastif), c’est–à–dire un apport informationnel impliquant une opposition paradigmatique. Le point de départ est la présentation et le commentaire des structures décrites par les grammaires et les différentes études pragmatiques comme étant adaptées à l’expression du contraste en italien: l’antéposition du focus, le clivage et la postposi...

  9. Lissage de la marge agricole par une provision comptable

    OpenAIRE

    Phélippé-Guinvarc’h, Martial V.

    2008-01-01

    Les producteurs agricoles connaissent de fortes variations de leurs marges opérationnelles, qui peuvent entraîner des pertes financières. Pourtant, le contexte réglementaire actuel français ne permet pas de constituer une provision comptable pour les risques sur la marge. Cet article recommande la constitution d’une nouvelle provision :  la provision pour fluctuation systémique de la marge. Il souligne que cette provision respecte les principes fondateurs de la comptabilité et de la fiscalité...

  10. Développement et diversification d’une onomastique politique

    OpenAIRE

    Bacot, Paul

    2012-01-01

    Si l’onomastique a toujours intéressé les linguistes, ceux-ci s’en sont longtemps tenus à l’étude des seuls noms de lieux (toponymes), de personnes (anthroponymes) et de peuples (ethnonymes). La science politique, quant à elle, a jusqu’à une date récente très largement délaissé ce champ de recherche. L’onomastique politique a pourtant toute sa place dans une politologie lexicale elle-même indissociable des autres approches de la sociologie du politique. Dans cette perspective, nombreux sont, ...

  11. Les travailleurs de la nature : une professionnalisation en tension

    Directory of Open Access Journals (Sweden)

    Arnaud Cosson

    2010-12-01

    Full Text Available En France, le développement des métiers de la nature est lié à une opposition, parfois violente, à la bureaucratie et au recours croissant à la technique. Pourtant, on constate aujourd’hui un mouvement de rationalisation, de technicisation et de professionnalisation de ces activités, bien loin de l’image mythifiée d’activités qui seraient caractérisées essentiellement par l’engagement, la passion ou la proximité au terrain. C’est ainsi l’alignement avec d’autres corps de métiers qui est mis en avant par les acteurs travaillant dans des espaces naturels qui témoignent de leur volonté de (se convaincre que leur activité constitue un « vrai travail », un « vrai métier ».En nous basant sur une enquête empirique complétant un ensemble de travaux antérieurs, nous éclairons la façon dont cette tension – entre passion et rationalisation, entre spécificité et alignement – s’exprime dans le vécu et les pratiques des professionnels de la nature en France. Nous explorons trois niveaux : celui des conditions de l’engagement dans le métier (tendues entre revendication de compétences et de qualifications et mise en avant d’une passion ; celui des figures et des identités professionnelles (prises entre figure de l’expert naturaliste et figure du médiateur ; celui des pratiques de travail (oscillant entre pratiques néo-manageriales et proximité à la nature.Ce faisant, nous esquissons les contours d’une forme de professionnalisation singulière et paradoxale, propre aux métiers de la nature, qui s’est construite sur une tension constitutive entre rationalisation et résistance à la rationalisation, entre alignement sur les standards d’autres professions et maintien d’une spécificité.Nature jobs: a professionalization under stressThe development of nature jobs in France is linked to a sometimes fierce opposition to bureaucracy and the rising resort to technology. However, these jobs

  12. Soil texture reclassification by an ensemble model

    Science.gov (United States)

    Cisty, Milan; Hlavcova, Kamila

    2015-04-01

    a prerequisite for solving some subsequent task, this bias is propagated to the subsequent modelling or other work. Therefore, for the sake of achieving more general and precise outputs while solving such tasks, the authors of the present paper are proposing a hybrid approach, which has the potential for obtaining improved results. Although the authors continue recommending the use of the mentioned parametric PSD models in the proposed methodology, the final prediction is made by an ensemble machine learning algorithm based on regression trees, the so-called Random Forest algorithm, which is built on top of the outputs of such models, which serves as an ensemble members. An improvement in precision was proved, and it is documented in the paper that the ensemble model worked better than any of its constituents. References Nemes, A., Wosten, J.H.M., Lilly, A., Voshaar, J.H.O.: Evaluation of different procedures to interpolate particle-size distributions to achieve compatibility within soil databases. Geoderma 90, 187- 202 (1999) Hwang, S.: Effect of texture on the performance of soil particle-size distribution models. Geoderma 123, 363-371 (2004) Botula, Y.D., Cornelis, W.M., Baert, G., Mafuka, P., Van Ranst, E.: Particle size distribution models for soils of the humid tropics. J Soils Sediments. 13, 686-698 (2013)

  13. Ensemble-type numerical uncertainty information from single model integrations

    Energy Technology Data Exchange (ETDEWEB)

    Rauser, Florian, E-mail: florian.rauser@mpimet.mpg.de; Marotzke, Jochem; Korn, Peter

    2015-07-01

    We suggest an algorithm that quantifies the discretization error of time-dependent physical quantities of interest (goals) for numerical models of geophysical fluid dynamics. The goal discretization error is estimated using a sum of weighted local discretization errors. The key feature of our algorithm is that these local discretization errors are interpreted as realizations of a random process. The random process is determined by the model and the flow state. From a class of local error random processes we select a suitable specific random process by integrating the model over a short time interval at different resolutions. The weights of the influences of the local discretization errors on the goal are modeled as goal sensitivities, which are calculated via automatic differentiation. The integration of the weighted realizations of local error random processes yields a posterior ensemble of goal approximations from a single run of the numerical model. From the posterior ensemble we derive the uncertainty information of the goal discretization error. This algorithm bypasses the requirement of detailed knowledge about the models discretization to generate numerical error estimates. The algorithm is evaluated for the spherical shallow-water equations. For two standard test cases we successfully estimate the error of regional potential energy, track its evolution, and compare it to standard ensemble techniques. The posterior ensemble shares linear-error-growth properties with ensembles of multiple model integrations when comparably perturbed. The posterior ensemble numerical error estimates are of comparable size as those of a stochastic physics ensemble.

  14. Diagnostic studies of ensemble forecast "jumps"

    Science.gov (United States)

    Magnusson, Linus; Hewson, Tim; Ferranti, Laura; Rodwell, Mark

    2016-04-01

    During 2015 we saw exceptional consistency in successive seasonal forecasts produced at ECMWF, for the winter period 2015/16, right across the globe. This winter was characterised by a well-predicted and unusually strong El Nino, and some have ascribed the consistency to that. For most of December this consistency was mirrored in the (separate) ECMWF monthly forecast system, which correctly predicted anomalously strong (mild) zonal flow, over the North Atlantic and western Eurasia, even in forecasts for weeks 3 and 4. In monthly forecasts in general these weeks are often devoid of strong signals. However in late December and early January strong signals, even in week 2, proved to be incorrect, most notably over the North Atlantic and Eurasian sectors. Indeed on at least two occasions the outcome was beyond the ensemble forecast range over Scandinavia. In one of these conditions flipped from extreme mild to extreme cold as a high latitude block developed. Temperature prediction is very important to many customers, notably those dealing with renewable energy, because cold weather causes increased demand but also tends to coincide with reduced wind power production. So understandably jumps can cause consternation amongst some customer groups, and are very difficult to handle operationally. This presentation will discuss the results of initial diagnostic investigations into what caused the "ensemble jumps", particularly at the week two lead, though reference will also be made to a related shorter range (day 3) jump that was important for flooding over the UK. Initial results suggest that an inability of the ECMWF model to correctly represent convective outbreaks over North America (that for winter-time were quite extreme) played an important role. Significantly, during this period, an unusually large amount of upper air data over North America was rejected or ascribed low weight. These results bear similarities to previous diagnostic studies at ECMWF, wherein major

  15. Construction of High-accuracy Ensemble of Classifiers

    Directory of Open Access Journals (Sweden)

    Hedieh Sajedi

    2014-04-01

    Full Text Available There have been several methods developed to construct ensembles. Some of these methods, such as Bagging and Boosting are meta-learners, i.e. they can be applied to any base classifier. The combination of methods should be selected in order that classifiers cover each other weaknesses. In ensemble, the output of several classifiers is used only when they disagree on some inputs. The degree of disagreement is called diversity of the ensemble. Another factor that plays a significant role in performing an ensemble is accuracy of the basic classifiers. It can be said that all the procedures of constructing ensembles seek to achieve a balance between these two parameters, and successful methods can reach a better balance. The diversity of the members of an ensemble is known as an important factor in determining its generalization error. In this paper, we present a new approach for generating ensembles. The proposed approach uses Bagging and Boosting as the generators of base classifiers. Subsequently, the classifiers are partitioned by means of a clustering algorithm. We introduce a selection phase for construction the final ensemble and three different selection methods are proposed for applying in this phase. In the first proposed selection method, a classifier is selected randomly from each cluster. The second method selects the most accurate classifier from each cluster and the third one selects the nearest classifier to the center of each cluster to construct the final ensemble. The results of the experiments on well-known datasets demonstrate the strength of our proposed approach, especially applying the selection of the most accurate classifiers from clusters and employing Bagging generator.

  16. Jeunes, violence et société. Analyse du discours de la Chambre des Représentants entre 1981 et 1999 dans une perspective de criminologie critique.

    OpenAIRE

    Nagels, Carla

    2004-01-01

    Fidèle à notre orientation sociologique et criminologique, cette recherche s’inscrit dans une perspective critique. C’est-à-dire dans un courant de pensée qui conçoit la société, non pas comme un tout homogène, non pas comme un ensemble d’individus en interrelation, mais bien comme l’expression de rapports conflictuels entre groupes sociaux, comme l’expression de rapports de domination. La thèse analyse le discours de la Chambre des représentants de 1981 à 1999. Elle pose comme hypothèse g...

  17. Expérience de transfert de savoirs et de technologies issus de la recherche et de l'industrie aux étudiants d'une formation en IHM

    OpenAIRE

    Pinna-Déry, Anne-Marie; Giboin, Alain; Renevier-Gonin, Philippe; Brel, Christian; Da Costa, Macha

    2011-01-01

    Cet article présente un retour d'expérience sur une formation en IHM de niveau Master 2 et École d'ingénieurs reposant sur le transfert de savoirs et de technologies issus de la recherche et de l'industrie. Nous mettons l'accent sur l'importance de former les étudiants à des domaines de recherche prometteurs tels que la plasticité des IHM et à des technologies récentes permettant le développement d'applications sur supports mobiles et table MS Surface. L'ensemble de la formation valorise les ...

  18. Ensemble Deep Learning for Biomedical Time Series Classification

    Directory of Open Access Journals (Sweden)

    Lin-peng Jin

    2016-01-01

    Full Text Available Ensemble learning has been proved to improve the generalization ability effectively in both theory and practice. In this paper, we briefly outline the current status of research on it first. Then, a new deep neural network-based ensemble method that integrates filtering views, local views, distorted views, explicit training, implicit training, subview prediction, and Simple Average is proposed for biomedical time series classification. Finally, we validate its effectiveness on the Chinese Cardiovascular Disease Database containing a large number of electrocardiogram recordings. The experimental results show that the proposed method has certain advantages compared to some well-known ensemble methods, such as Bagging and AdaBoost.

  19. An Improved Particle Swarm Optimization Algorithm Based on Ensemble Technique

    Institute of Scientific and Technical Information of China (English)

    SHI Yan; HUANG Cong-ming

    2006-01-01

    An improved particle swarm optimization (PSO) algorithm based on ensemble technique is presented. The algorithm combines some previous best positions (pbest) of the particles to get an ensemble position (Epbest), which is used to replace the global best position (gbest). It is compared with the standard PSO algorithm invented by Kennedy and Eberhart and some improved PSO algorithms based on three different benchmark functions. The simulation results show that the improved PSO based on ensemble technique can get better solutions than the standard PSO and some other improved algorithms under all test cases.

  20. Filtering single atoms from Rydberg blockaded mesoscopic ensembles

    CERN Document Server

    Petrosyan, David; Mølmer, Klaus

    2015-01-01

    We propose an efficient method to filter out single atoms from trapped ensembles with unknown number of atoms. The method employs stimulated adiabatic passage to reversibly transfer a single atom to the Rydberg state which blocks subsequent Rydberg excitation of all the other atoms within the ensemble. This triggers the excitation of Rydberg blockaded atoms to short lived intermediate states and their subsequent decay to untrapped states. Using an auxiliary microwave field to carefully engineer the dissipation, we obtain a nearly deterministic single-atom source. Our method is applicable to small atomic ensembles in individual microtraps and in lattice arrays.

  1. Deterministic entanglement of Rydberg ensembles by engineered dissipation

    DEFF Research Database (Denmark)

    Dasari, Durga; Mølmer, Klaus

    2014-01-01

    We propose a scheme that employs dissipation to deterministically generate entanglement in an ensemble of strongly interacting Rydberg atoms. With a combination of microwave driving between different Rydberg levels and a resonant laser coupling to a short lived atomic state, the ensemble can...... be driven towards a dark steady state that entangles all atoms. The long-range resonant dipole-dipole interaction between different Rydberg states extends the entanglement beyond the van der Walls interaction range with perspectives for entangling large and distant ensembles....

  2. Ensemble Deep Learning for Biomedical Time Series Classification

    Science.gov (United States)

    2016-01-01

    Ensemble learning has been proved to improve the generalization ability effectively in both theory and practice. In this paper, we briefly outline the current status of research on it first. Then, a new deep neural network-based ensemble method that integrates filtering views, local views, distorted views, explicit training, implicit training, subview prediction, and Simple Average is proposed for biomedical time series classification. Finally, we validate its effectiveness on the Chinese Cardiovascular Disease Database containing a large number of electrocardiogram recordings. The experimental results show that the proposed method has certain advantages compared to some well-known ensemble methods, such as Bagging and AdaBoost.

  3. Veulent-ils encore une carte de presse ? Les jeunes journalistes de Belgique francophone

    Directory of Open Access Journals (Sweden)

    Olivier Standaert

    2013-12-01

    Full Text Available Cet article questionne les formes identitaires développées par les jeunes journalistesbelges lorsque se pose à eux la question de la possession de la carte de presse. La méthodologie s’appuie sur une étude descriptive du profil professionnel des jeunes journalistes et sur des entretiens non directifs menés auprès de journalistes, encartés ou non, ayant moins de cinq ans d’ancienneté. Il apparaît qu’une part importante d’entre eux ne répond plus, et ce durant une période de plus en plus longue, aux critères stricts d’obtention de la carte de presse tels que définis par les autorités belges. La carte de presse est par conséquent souvent sollicitée après l’insertion effective sur le marché du travail. Ceci peut s’expliquer par la précarisation des conditions d’insertion dans le groupe professionnel des journalistes. La montée de la précarisation au sein des médias d’information générale est une des hypothèses explicatives du décalage fréquemment constaté entre les formes identitaires traditionnelles, attachées à la carte de presse, et celles des jeunes journalistes, dominées par la figure de l’individu précaire, flexible et substituable en dépit d’une vocation affichée. Les entretiens mettent cependant en évidence un discours ambivalent où une rhétorique d’indifférence, de questionnement, voire de rejet par rapport à tout document se donnant un pouvoir d’authentifier qui est journaliste et qui ne l’est pas, côtoie un discours de conciliation et d’adhésion, mettant en avant la force symbolique de cette carte et la forme d’aboutissement identitaire que sa délivrance continue d’incarner. Il est significatif de noter que les instances d’agréation adaptent leurs pratiques, plus que leurs discours, à ces nouvelles situations professionnelles et aux identités qui en découlent : la délivrance de la carte de presse se fait de plus en plus au cas par cas, et avec une certaine

  4. Ensemble estimators for multivariate entropy estimation

    CERN Document Server

    Sricharan, Kumar

    2012-01-01

    The problem of estimation of density functionals like entropy and mutual information has received much attention in the statistics and information theory communities. A large class of estimators of functionals of the probability density suffer from the curse of dimensionality, wherein the exponent in the MSE rate of convergence decays increasingly slowly as the dimension $d$ of the samples increases. In particular, the rate is often glacially slow of order $O(T^{-{\\gamma}/{d}})$, where $T$ is the number of samples, and $\\gamma>0$ is a rate parameter. Examples of such estimators include kernel density estimators, $k$-NN density estimators, $k$-NN entropy estimators, intrinsic dimension estimators and other examples. In this paper, we propose a weighted convex combination of an ensemble of such estimators, where optimal weights can be chosen such that the weighted estimator converges at a much faster dimension invariant rate of $O(T^{-1})$. Furthermore, we show that these optimal weights can be determined by so...

  5. Asymptotic expansions for the Gaussian unitary ensemble

    DEFF Research Database (Denmark)

    Haagerup, Uffe; Thorbjørnsen, Steen

    2012-01-01

    Let g : R ¿ C be a C8-function with all derivatives bounded and let trn denote the normalized trace on the n × n matrices. In Ref. 3 Ercolani and McLaughlin established asymptotic expansions of the mean value ¿{trn(g(Xn))} for a rather general class of random matrices Xn, including the Gaussian...... Unitary Ensemble (GUE). Using an analytical approach, we provide in the present paper an alternative proof of this asymptotic expansion in the GUE case. Specifically we derive for a random matrix Xn that where k is an arbitrary positive integer. Considered as mappings of g, we determine the coefficients...... aj(g), j ¿ N, as distributions (in the sense of L. Schwarts). We derive a similar asymptotic expansion for the covariance Cov{Trn[f(Xn)], Trn[g(Xn)]}, where f is a function of the same kind as g, and Trn = n trn. Special focus is drawn to the case where and for ¿, µ in C\\R. In this case the mean and...

  6. Variety of synchronous regimes in neuronal ensembles

    Science.gov (United States)

    Komarov, M. A.; Osipov, G. V.; Suykens, J. A. K.

    2008-09-01

    We consider a Hodgkin-Huxley-type model of oscillatory activity in neurons of the snail Helix pomatia. This model has a distinctive feature: It demonstrates multistability in oscillatory and silent modes that is typical for the thalamocortical neurons. A single neuron cell can demonstrate a variety of oscillatory activity: Regular and chaotic spiking and bursting behavior. We study collective phenomena in small and large arrays of nonidentical cells coupled by models of electrical and chemical synapses. Two single elements coupled by electrical coupling show different types of synchronous behavior, in particular in-phase and antiphase synchronous regimes. In an ensemble of three inhibitory synaptically coupled elements, the phenomenon of sequential synchronous dynamics is observed. We study the synchronization phenomena in the chain of nonidentical neurons at different oscillatory behavior coupled with electrical and chemical synapses. Various regimes of phase synchronization are observed: (i) Synchronous regular and chaotic spiking; (ii) synchronous regular and chaotic bursting; and (iii) synchronous regular and chaotic bursting with different numbers of spikes inside the bursts. We detect and study the effect of collective synchronous burst generation due to the cluster formation and the oscillatory death.

  7. Model error estimation in ensemble data assimilation

    Directory of Open Access Journals (Sweden)

    S. Gillijns

    2007-01-01

    Full Text Available A new methodology is proposed to estimate and account for systematic model error in linear filtering as well as in nonlinear ensemble based filtering. Our results extend the work of Dee and Todling (2000 on constant bias errors to time-varying model errors. In contrast to existing methodologies, the new filter can also deal with the case where no dynamical model for the systematic error is available. In the latter case, the applicability is limited by a matrix rank condition which has to be satisfied in order for the filter to exist. The performance of the filter developed in this paper is limited by the availability and the accuracy of observations and by the variance of the stochastic model error component. The effect of these aspects on the estimation accuracy is investigated in several numerical experiments using the Lorenz (1996 model. Experimental results indicate that the availability of a dynamical model for the systematic error significantly reduces the variance of the model error estimates, but has only minor effect on the estimates of the system state. The filter is able to estimate additive model error of any type, provided that the rank condition is satisfied and that the stochastic errors and measurement errors are significantly smaller than the systematic errors. The results of this study are encouraging. However, it remains to be seen how the filter performs in more realistic applications.

  8. Protective clothing ensembles and physical employment standards.

    Science.gov (United States)

    McLellan, Tom M; Havenith, George

    2016-06-01

    Physical employment standards (PESs) exist for certain occupational groups that also require the use of protective clothing ensembles (PCEs) during their normal work. This review addresses whether these current PESs appropriately incorporate the physiological burden associated with wearing PCEs during respective tasks. Metabolic heat production increases because of wearing PCE; this increase is greater than that because of simply the weight of the clothing and can vary 2-fold among individuals. This variation negates a simple adjustment to the PES for the effect of the clothing on metabolic rate. As a result, PES testing that only simulates the weight of the clothing and protective equipment does not adequately accommodate this effect. The physiological heat strain associated with the use of PCEs is also not addressed with current PESs. Typically the selection tests of a PES lasts less than 20 min, whereas the requirement for use of PCE in the workplace may approach 1 h before cooling strategies can be employed. One option that might be considered is to construct a heat stress test that requires new recruits and incumbents to work for a predetermined duration while exposed to a warm environmental temperature while wearing the PCE. PMID:27277562

  9. Emergent order in ensembles of active spinners

    Science.gov (United States)

    van Zuiden, Benjamin C.; Paulose, Jayson; Irvine, William T. M.; Bartolo, Denis; Vitelli, Vincenzo

    Interacting self-propelled particles is proxy to model many living systems from cytoskeletal motors to bird flocks, while also providing a framework to investigate fundamental questions in non equilibrium statistical mechanics. A surge of recent studies have shown that self-propulsion significantly modifies the phase behavior of particles interacting via potential interactions. A prototypical example is the so-called Motility Induced Phase Separation occurring in ensembles of self-propelled hard spheres. In stark contrast, our understanding of active spinning, as opposed to self-propulsion, remains very scarce. Here, we study a system of self-spinning dimers, interacting via soft repulsive forces. Upon varying the density and activity, we observe a range of emergent phases characterized by different degrees of spatiotemporal order in the position and orientation of the dimers. Changes in bulk properties, including crystallization, melting, and freezing, are reflected in the collective motion of the particles. We rationalize our numerical findings theoretically and demonstrate some of these concepts in a active granular experiment.

  10. Cluster ensembles, quantization and the dilogarithm

    DEFF Research Database (Denmark)

    Fock, Vladimir; Goncharov, Alexander B.

    2009-01-01

    A cluster ensemble is a pair of positive spaces (i.e. varieties equipped with positive atlases), coming with an action of a symmetry group . The space is closely related to the spectrum of a cluster algebra [ 12 ]. The two spaces are related by a morphism . The space is equipped with a closed -form...... the algebra of functions on the -deformed -space has a large center, which includes the algebra of functions on the original -space. The main example is provided by the pair of moduli spaces assigned in [ 7 ] to a topological surface with a finite set of points at the boundary and a split semisimple algebraic...... group . It is an algebraic-geometric avatar of higher Teichmüller theory on related to . We suggest that there exists a duality between the and spaces. In particular, we conjecture that the tropical points of one of the spaces parametrise a basis in the space of functions on the Langlands dual space. We...

  11. Orchestrating Distributed Resource Ensembles for Petascale Science

    Energy Technology Data Exchange (ETDEWEB)

    Baldin, Ilya; Mandal, Anirban; Ruth, Paul; Yufeng, Xin

    2014-04-24

    Distributed, data-intensive computational science applications of interest to DOE scientific com- munities move large amounts of data for experiment data management, distributed analysis steps, remote visualization, and accessing scientific instruments. These applications need to orchestrate ensembles of resources from multiple resource pools and interconnect them with high-capacity multi- layered networks across multiple domains. It is highly desirable that mechanisms are designed that provide this type of resource provisioning capability to a broad class of applications. It is also important to have coherent monitoring capabilities for such complex distributed environments. In this project, we addressed these problems by designing an abstract API, enabled by novel semantic resource descriptions, for provisioning complex and heterogeneous resources from multiple providers using their native provisioning mechanisms and control planes: computational, storage, and multi-layered high-speed network domains. We used an extensible resource representation based on semantic web technologies to afford maximum flexibility to applications in specifying their needs. We evaluated the effectiveness of provisioning using representative data-intensive ap- plications. We also developed mechanisms for providing feedback about resource performance to the application, to enable closed-loop feedback control and dynamic adjustments to resource allo- cations (elasticity). This was enabled through development of a novel persistent query framework that consumes disparate sources of monitoring data, including perfSONAR, and provides scalable distribution of asynchronous notifications.

  12. General approaches in ensemble quantum computing

    Indian Academy of Sciences (India)

    V Vimalan; N Chandrakumar

    2008-01-01

    We have developed methodology for NMR quantum computing focusing on enhancing the efficiency of initialization, of logic gate implementation and of readout. Our general strategy involves the application of rotating frame pulse sequences to prepare pseudopure states and to perform logic operations. We demonstrate experimentally our methodology for both homonuclear and heteronuclear spin ensembles. On model two-spin systems, the initialization time of one of our sequences is three-fourths (in the heteronuclear case) or one-fourth (in the homonuclear case), of the typical pulsed free precession sequences, attaining the same initialization efficiency. We have implemented the logical SWAP operation in homonuclear AMX spin systems using selective isotropic mixing, reducing the duration taken to a third compared to the standard re-focused INEPT-type sequence. We introduce the 1D version for readout of the rotating frame SWAP operation, in an attempt to reduce readout time. We further demonstrate the Hadamard mode of 1D SWAP, which offers 2N-fold reduction in experiment time for a system with -working bits, attaining the same sensitivity as the standard 1D version.

  13. Une autre ville pour une autre vie. Henri Lefebvre et les situationnistes

    Directory of Open Access Journals (Sweden)

    Philippe Simay

    2008-12-01

    Full Text Available L’un des traits distinctifs du mouvement situationniste est de s’être constamment préoccupé de la question urbaine. Conçue comme l’espace de production de la société du spectacle mais aussi comme un terrain de lutte et d’expérimentation, la ville a représenté pour ce mouvement estudiantin, proche d’Henri Lefebvre, le lieu d’une réinvention radicale de la vie quotidienne. Cet article revient sur la critique situationniste de l’urbanisme de l’après-guerre ainsi que sur les pratiques auxquelles elle a donné lieu (détournement, dérive, cartes psychogéographiques, construction de situations éphémères. Celles-ci peuvent être regardées comme la première expression d’un « droit à la ville », tel que l’entendait Lefebvre. Reste à savoir si le groupe de Guy Debord souhaitait véritablement « changer la ville pour changer la vie » ou si la ville n’était que le théâtre d’une révolution à venir.One of the distinctive traits of the situationist movement is its constant preoccupation with the urban issue. For this student movement close to Henri Lefebvre, the city has been thought of as a choice generic location for the production of the Society of the Spectacle, but also as a test ground for struggle and experimentation – the place where a radical reinvention of daily life can occur. This paper goes back to the situationist critique of post-war urbanism, as well as the behaviors and practices it has given birth to (misappropriation, drifts in meaning, psychogeographic maps, the construct of short-lived situations. These can be seen as the first expression of a « right to the city », in the sense Lefebvre originally meant it have. However, it is still unknown whether Guy Debord's group really wished to « change city-life to change life itself », or if to them the city was merely a theater for the enactment of a revolution to come.

  14. PSYCHOANALYSE ET LITTÉRATURE : pour une discipline moderniste

    Directory of Open Access Journals (Sweden)

    Sjef Houppermans

    2010-05-01

    Full Text Available Cet article propose un panorama de la relation entre la théorie psychanalytique et la critique littéraire, à la fois historique et systématique. Les résultats en sont confrontés à une lecture du roman policier.

  15. Une approche bergsonienne de la spatialité en musique

    Directory of Open Access Journals (Sweden)

    Pierre Truchot

    2006-04-01

    Full Text Available Il s’agit d’apporter une contribution afin de définir la nature de l’espace sonore créé par certaines musiques contemporaines. Cet espace sonore proposant une spécificité qualitative sans commune mesure avec notre expérience quotidienne et habituelle de l’espace ; l’approche et les moyens mis en œuvre pour parvenir à une définition de cette spécificité qualitative peuvent apparaître comme une gageure puisque nous nous appuierons sur les analyses bergsoniennes de l’espace pour déterminer précisément la nature qualitative de la spatialité en musique. En effet, si Bergson attribue à l’espace des propriétés antithétiques à celles que les musicologues reconnaissent à l’espace musical, en revanche la notion d’étendue – telle qu’elle est définie par Bergson – semble particulièrement appropriée pour penser l’espace sonore musical.

  16. Contestation des Nobel une tradition aussi ancienne que leur attribution

    CERN Multimedia

    Sevestre, G

    2003-01-01

    "La contestation des Nobel, avec cette annee la campagne lancee par un Americain afin de faire reconnaitre son role dans la mise au point de l'imagerie a resonance magnetique (IRM), constitue une tradition, quasiment aussi ancienne que l'attribution de ces distinctions" (1 page).

  17. La violence sociale est-elle une violence masculine

    OpenAIRE

    Ayral, Sylvie; Raibaud, Yves

    2011-01-01

    En s'appuyant sur des recherches portant d'une part sur les sanctions au collège, d'autre part sur les politiques publiques de prévention s'interrogent sur les représentations sociales de la violence masculine.

  18. Virtual Mobility in Higher Education. The UNED Campus Net Program

    Science.gov (United States)

    Aguado, Teresa; Monge, Fernando; Del Olmo, Alicia

    2014-01-01

    We present the UNED Virtual Mobility Campus Net Program, implemented since 2012 in collaboration with European and Latin American universities. Program's objectives, participating institutions, procedures, and evaluation are exposed. Virtual mobility is understood as a meaningful strategy for intercultural learning by studying an undergraduate or…

  19. A past discharge assimilation system for ensemble streamflow forecasts over France – Part 2: Impact on the ensemble streamflow forecasts

    Directory of Open Access Journals (Sweden)

    G. Thirel

    2010-08-01

    Full Text Available The use of ensemble streamflow forecasts is developing in the international flood forecasting services. Ensemble streamflow forecast systems can provide more accurate forecasts and useful information about the uncertainty of the forecasts, thus improving the assessment of risks. Nevertheless, these systems, like all hydrological forecasts, suffer from errors on initialization or on meteorological data, which lead to hydrological prediction errors. This article, which is the second part of a 2-part article, concerns the impacts of initial states, improved by a streamflow assimilation system, on an ensemble streamflow prediction system over France. An assimilation system was implemented to improve the streamflow analysis of the SAFRAN-ISBA-MODCOU (SIM hydro-meteorological suite, which initializes the ensemble streamflow forecasts at Météo-France. This assimilation system, using the Best Linear Unbiased Estimator (BLUE and modifying the initial soil moisture states, showed an improvement of the streamflow analysis with low soil moisture increments. The final states of this suite were used to initialize the ensemble streamflow forecasts of Météo-France, which are based on the SIM model and use the European Centre for Medium-range Weather Forecasts (ECMWF 10-day Ensemble Prediction System (EPS. Two different configurations of the assimilation system were used in this study: the first with the classical SIM model and the second using improved soil physics in ISBA. The effects of the assimilation system on the ensemble streamflow forecasts were assessed for these two configurations, and a comparison was made with the original (i.e. without data assimilation and without the improved physics ensemble streamflow forecasts. It is shown that the assimilation system improved most of the statistical scores usually computed for the validation of ensemble predictions (RMSE, Brier Skill Score and its decomposition, Ranked Probability Skill Score, False Alarm

  20. In Brief: Science teaching certificate

    Science.gov (United States)

    Showstack, Randy

    2008-11-01

    More than 200 educators will receive fellowships over the next 5 years to participate in NASA's Endeavor Science Teaching Certificate Project, the agency announced on 14 November. Through workshops, online and on-site graduate courses, and NASA educational materials, the project will expose educators to NASA science and engineering and support them in translating the information for use in classrooms. ``Through the program, educators will learn to deliver cutting-edge science into the classroom, promoting science, technology, engineering, and mathematics education,'' according to Joyce Winterton, assistant administrator for education at NASA Headquarters, in Washington, D. C. Project fellows will earn a certificate from Teachers College Innovations at Teachers College, Columbia University, New York, and graduate credit from other institutional partners. For more information, visit http://education.nasa.gov/home/index.html.

  1. Spectroscopic properties of inhomogeneously broadened spin ensembles in a cavity

    DEFF Research Database (Denmark)

    Kurucz, Zoltan; Wesenberg, Janus; Mølmer, Klaus

    2011-01-01

    The enhanced collective coupling to weak quantum fields may turn atomic or spin ensembles into an important component in quantum information processing architectures. Inhomogeneous broadening can, however, significantly reduce the coupling and the lifetime of the collective excitation...

  2. Phase-selective entrainment of nonlinear oscillator ensembles

    Science.gov (United States)

    Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z.; Li-Shin, Jr.

    2016-03-01

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.

  3. Prediction of Weather Impacted Airport Capacity using Ensemble Learning

    Science.gov (United States)

    Wang, Yao Xun

    2011-01-01

    Ensemble learning with the Bagging Decision Tree (BDT) model was used to assess the impact of weather on airport capacities at selected high-demand airports in the United States. The ensemble bagging decision tree models were developed and validated using the Federal Aviation Administration (FAA) Aviation System Performance Metrics (ASPM) data and weather forecast at these airports. The study examines the performance of BDT, along with traditional single Support Vector Machines (SVM), for airport runway configuration selection and airport arrival rates (AAR) prediction during weather impacts. Testing of these models was accomplished using observed weather, weather forecast, and airport operation information at the chosen airports. The experimental results show that ensemble methods are more accurate than a single SVM classifier. The airport capacity ensemble method presented here can be used as a decision support model that supports air traffic flow management to meet the weather impacted airport capacity in order to reduce costs and increase safety.

  4. Time and ensemble averaging in time series analysis

    CERN Document Server

    Latka, Miroslaw; Jernajczyk, Wojciech; West, Bruce J

    2010-01-01

    In many applications expectation values are calculated by partitioning a single experimental time series into an ensemble of data segments of equal length. Such single trajectory ensemble (STE) is a counterpart to a multiple trajectory ensemble (MTE) used whenever independent measurements or realizations of a stochastic process are available. The equivalence of STE and MTE for stationary systems was postulated by Wang and Uhlenbeck in their classic paper on Brownian motion (Rev. Mod. Phys. 17, 323 (1945)) but surprisingly has not yet been proved. Using the stationary and ergodic paradigm of statistical physics -- the Ornstein-Uhlenbeck (OU) Langevin equation, we revisit Wang and Uhlenbeck's postulate. In particular, we find that the variance of the solution of this equation is different for these two ensembles. While the variance calculated using the MTE quantifies the spreading of independent trajectories originating from the same initial point, the variance for STE measures the spreading of two correlated r...

  5. An educational model for ensemble streamflow simulation and uncertainty analysis

    Directory of Open Access Journals (Sweden)

    A. AghaKouchak

    2012-06-01

    Full Text Available This paper presents a hands-on modeling toolbox, HBV-Ensemble, designed as a complement to theoretical hydrology lectures, to teach hydrological processes and their uncertainties. The HBV-Ensemble can be used for in-class lab practices and homework assignments, and assessment of students' understanding of hydrological processes. Using this model, students can gain more insights into how hydrological processes (e.g., precipitation, snowmelt and snow accumulation, soil moisture, evapotranspiration and runoff generation are interconnected. The model includes a MATLAB Graphical User Interface (GUI and an ensemble simulation scheme that can be used for not only hydrological processes, but also for teaching uncertainty analysis, parameter estimation, ensemble simulation and model sensitivity.

  6. Ensembles on configuration space classical, quantum, and beyond

    CERN Document Server

    Hall, Michael J W

    2016-01-01

    This book describes a promising approach to problems in the foundations of quantum mechanics, including the measurement problem. The dynamics of ensembles on configuration space is shown here to be a valuable tool for unifying the formalisms of classical and quantum mechanics, for deriving and extending the latter in various ways, and for addressing the quantum measurement problem. A description of physical systems by means of ensembles on configuration space can be introduced at a very fundamental level: the basic building blocks are a configuration space, probabilities, and Hamiltonian equations of motion for the probabilities. The formalism can describe both classical and quantum systems, and their thermodynamics, with the main difference being the choice of ensemble Hamiltonian. Furthermore, there is a natural way of introducing ensemble Hamiltonians that describe the evolution of hybrid systems; i.e., interacting systems that have distinct classical and quantum sectors, allowing for consistent descriptio...

  7. Ensemble vs. time averages in financial time series analysis

    Science.gov (United States)

    Seemann, Lars; Hua, Jia-Chen; McCauley, Joseph L.; Gunaratne, Gemunu H.

    2012-12-01

    Empirical analysis of financial time series suggests that the underlying stochastic dynamics are not only non-stationary, but also exhibit non-stationary increments. However, financial time series are commonly analyzed using the sliding interval technique that assumes stationary increments. We propose an alternative approach that is based on an ensemble over trading days. To determine the effects of time averaging techniques on analysis outcomes, we create an intraday activity model that exhibits periodic variable diffusion dynamics and we assess the model data using both ensemble and time averaging techniques. We find that ensemble averaging techniques detect the underlying dynamics correctly, whereas sliding intervals approaches fail. As many traded assets exhibit characteristic intraday volatility patterns, our work implies that ensemble averages approaches will yield new insight into the study of financial markets’ dynamics.

  8. HIGH-RESOLUTION ATMOSPHERIC ENSEMBLE MODELING AT SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Werth, D.; Chiswell, S.; Etherton, B.

    2011-05-10

    The High-Resolution Mid-Atlantic Forecasting Ensemble (HME) is a federated effort to improve operational forecasts related to precipitation, convection and boundary layer evolution, and fire weather utilizing data and computing resources from a diverse group of cooperating institutions in order to create a mesoscale ensemble from independent members. Collaborating organizations involved in the project include universities, National Weather Service offices, and national laboratories, including the Savannah River National Laboratory (SRNL). The ensemble system is produced from an overlapping numerical weather prediction model domain and parameter subsets provided by each contributing member. The coordination, synthesis, and dissemination of the ensemble information are performed by the Renaissance Computing Institute (RENCI) at the University of North Carolina-Chapel Hill. This paper discusses background related to the HME effort, SRNL participation, and example results available from the RENCI website.

  9. Savannah River National Laboratory Involvement in the European ENSEMBLE Program

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R. L.; Addies, Robert P.

    2005-10-24

    Many atmospheric transport and dispersion models now exist to provide consequence assessment during emergency response to near-field releases. One way of estimating the uncertainty for a given forecast is to statistically analyze an ensemble of results from several models. ENSEMBLE is a European Union program that utilizes an internet-based system to ingest transport results from numerous modeling agencies. This paper addresses the involvement of the Savannah River National Laboratory (SRNL) in ENSEMBLE, and the resulting improvements in SRNL modeling capabilities. SRNL, the only United States agency involved in the ENSEMBLE program, uses a prognostic atmospheric numerical model (the Regional Atmospheric Modeling System, RAMS) to provide three-dimensional and time-varying meteorology as input to a stochastic Lagrangian particle mode . The model design used by SRNL is discussed, including recent upgrades to the system using parallel processing which allows for finer grid resolution in the generation of the meteorology.

  10. ISO 9001 certification forecasting models

    OpenAIRE

    Sampaio, Paulo; Saraiva, Pedro; Rodrigues, António Guimarães

    2011-01-01

    Purpose – ISO 9001 certification is nowadays considered to be one of the most effective tools that can be adopted for guiding the management of Quality Systems. The stunning growth observed by these standards all over the world confirms a strong polarization of enterprises’ interest in this practice. Owing to the wide incidence of this phenomenon, a deep investigation of ISO 9001 diffusion over time is of mandatory importance. The research here reported covers the development of s...

  11. 40 CFR 80.163 - Detergent certification options.

    Science.gov (United States)

    2010-07-01

    ... to approved State programs). (d) CARB-Based Certification. A valid certification under section 2257 of Title 13, California Code of Regulations (CARB certification) may be the basis for a certification... at the LAC specified in the CARB certification only in gasoline that meets the requirements...

  12. 46 CFR 189.60-40 - Duration of Convention certificates.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Duration of Convention certificates. 189.60-40 Section... VESSELS INSPECTION AND CERTIFICATION Certificates Under International Convention for Safety of Life at Sea, 1974 § 189.60-40 Duration of Convention certificates. (a) The following certificates are valid for...

  13. 46 CFR 91.60-40 - Duration of Convention certificates.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Duration of Convention certificates. 91.60-40 Section 91... VESSELS INSPECTION AND CERTIFICATION Certificates Under International Convention for Safety of Life at Sea, 1974 § 91.60-40 Duration of Convention certificates. (a) The following certificates are valid for...

  14. 46 CFR 71.75-15 - Posting of Convention certificates.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Posting of Convention certificates. 71.75-15 Section 71... AND CERTIFICATION Certificates Under the International Convention for Safety of Life at Sea, 1960 § 71.75-15 Posting of Convention certificates. (a) The certificates described in this subpart,...

  15. Certification-Based Process Analysis

    Science.gov (United States)

    Knight, Russell L.

    2013-01-01

    Space mission architects are often challenged with knowing which investment in technology infusion will have the highest return. Certification-based analysis (CBA) gives architects and technologists a means to communicate the risks and advantages of infusing technologies at various points in a process. Various alternatives can be compared, and requirements based on supporting streamlining or automation can be derived and levied on candidate technologies. CBA is a technique for analyzing a process and identifying potential areas of improvement. The process and analysis products are used to communicate between technologists and architects. Process means any of the standard representations of a production flow; in this case, any individual steps leading to products, which feed into other steps, until the final product is produced at the end. This sort of process is common for space mission operations, where a set of goals is reduced eventually to a fully vetted command sequence to be sent to the spacecraft. Fully vetting a product is synonymous with certification. For some types of products, this is referred to as verification and validation, and for others it is referred to as checking. Fundamentally, certification is the step in the process where one insures that a product works as intended, and contains no flaws.

  16. Clustering Categorical Data:A Cluster Ensemble Approach

    Institute of Scientific and Technical Information of China (English)

    He Zengyou(何增友); Xu Xiaofei; Deng Shengchun

    2003-01-01

    Clustering categorical data, an integral part of data mining,has attracted much attention recently. In this paper, the authors formally define the categorical data clustering problem as an optimization problem from the viewpoint of cluster ensemble, and apply cluster ensemble approach for clustering categorical data. Experimental results on real datasets show that better clustering accuracy can be obtained by comparing with existing categorical data clustering algorithms.

  17. Assessing creativity in computer music ensembles: a computational approach

    OpenAIRE

    Comajuncosas, Josep M.

    2016-01-01

    Over the last decade Laptop Orchestras and Mobile Ensembles have proliferated. As a result, a large body of research has arisen on infrastructure, evaluation, design principles and compositional methodologies for Computer Music Ensembles (CME). However, little has been addressed and very little is known about the challenges and opportunities provided by CMEs for creativity in musical performance. Therefore, one of the most common issues CMEs have to deal with is the lack of ...

  18. Sensitivity tests for an ensemble Kalman filter for aerosol assimilation

    OpenAIRE

    N. A. J. Schutgens; T. Miyoshi; Takemura, T.; Nakajima, T

    2010-01-01

    We present sensitivity tests for a global aerosol assimilation system utilizing AERONET observations of AOT (aerosol optical thickness) and AAE (aerosol Ångström exponent). The assimilation system employs an ensemble Kalman filter which requires optimization of three numerical parameters: ensemble size nens, local patch size npatch and inflation factor ρ. In addition, experiments are performed to test ...

  19. On the distribution of eigenvalues of certain matrix ensembles

    International Nuclear Information System (INIS)

    Invariant random matrix ensembles with weak confinement potentials of the eigenvalues, corresponding to indeterminate moment problems, are investigated. These ensembles are characterized by the fact that the mean density of eigenvalues tends to a continuous function with increasing matrix dimension contrary to the usual cases where it grows indefinitely. It is demonstrated that the standard asymptotic formulae are not applicable in these cases and that the asymptotic distribution of eigenvalues can deviate from the classical ones. (author)

  20. Alerte aux voleurs de sexe ! Anthropologie pragmatique d'une rumeur africaine

    OpenAIRE

    Bonhomme, Julien

    2009-01-01

    L'article est consacré au " vol de sexe ", une rumeur de sorcellerie qui a touché à plusieurs reprises une vingtaine de pays d'Afrique subsaharienne depuis les années 1970. Il montre que la rumeur est moins une anecdote prêtant à rire qu'une affaire exemplaire permettant de comprendre l'Afrique urbaine contemporaine, les formes de sociabilité et les modes de communication qu'elle suppose. L'article met en valeur ce qui en fait une histoire particulièrement " bonne à penser " et " bonne à raco...

  1. Monthly Ensembles in Algal Bloom Predictions on the Baltic Sea

    Science.gov (United States)

    Roiha, Petra; Westerlund, Antti; Stipa, Tapani

    2010-05-01

    In this work we explore the statistical features of monthly ensembles and their capability to predict biogeochemical conditions in the Baltic Sea. Operational marine environmental modelling has been considered hard, and consequently there are very few operational ecological models. Operational modelling of harmful algal blooms is harder still, since it is difficult to separate the algal species in models, and in general, very little is known of HAB properties. We present results of an ensemble approach to HAB forecasting in the Baltic, and discuss the applicability of the forecasting method to biochemical modelling. It turns out that HABs are indeed possible to forecast with useful accuracy. For modelling the algal blooms in Baltic Sea we used FMI operational 3-dimensional biogeochemical model to produce seasonal ensemble forecasts for different physical, chemical and biological variables. The modelled variables were temperature, salinity, velocity, silicate, phosphate, nitrate, diatoms, flagellates and two species of potentially toxic filamentous cyanobacteria nodularia spumigena and aphanizomenon flos-aquae. In this work we concentrate to the latter two. Ensembles were produced by running the biogeochemical model several times and forcing it on every run with different set of seasonal weather parameters from ECMWF's mathematically perturbed ensemble prediction forecasts. The ensembles were then analysed by statistical methods and the median, quartiles, minimum and maximum values were calculated for estimating the probable amounts of algae. Validation for the forecast method was made by comparing the final results against available and valid in-situ HAB data.

  2. Ensembles of a small number of conformations with relative populations

    Energy Technology Data Exchange (ETDEWEB)

    Vammi, Vijay, E-mail: vsvammi@iastate.edu; Song, Guang, E-mail: gsong@iastate.edu [Iowa State University, Bioinformatics and Computational Biology Program, Department of Computer Science (United States)

    2015-12-15

    In our previous work, we proposed a new way to represent protein native states, using ensembles of a small number of conformations with relative Populations, or ESP in short. Using Ubiquitin as an example, we showed that using a small number of conformations could greatly reduce the potential of overfitting and assigning relative populations to protein ensembles could significantly improve their quality. To demonstrate that ESP indeed is an excellent alternative to represent protein native states, in this work we compare the quality of two ESP ensembles of Ubiquitin with several well-known regular ensembles or average structure representations. Extensive amount of significant experimental data are employed to achieve a thorough assessment. Our results demonstrate that ESP ensembles, though much smaller in size comparing to regular ensembles, perform equally or even better sometimes in all four different types of experimental data used in the assessment, namely, the residual dipolar couplings, residual chemical shift anisotropy, hydrogen exchange rates, and solution scattering profiles. This work further underlines the significance of having relative populations in describing the native states.

  3. Evolutionary Ensemble for In Silico Prediction of Ames Test Mutagenicity

    Science.gov (United States)

    Chen, Huanhuan; Yao, Xin

    Driven by new regulations and animal welfare, the need to develop in silico models has increased recently as alternative approaches to safety assessment of chemicals without animal testing. This paper describes a novel machine learning ensemble approach to building an in silico model for the prediction of the Ames test mutagenicity, one of a battery of the most commonly used experimental in vitro and in vivo genotoxicity tests for safety evaluation of chemicals. Evolutionary random neural ensemble with negative correlation learning (ERNE) [1] was developed based on neural networks and evolutionary algorithms. ERNE combines the method of bootstrap sampling on training data with the method of random subspace feature selection to ensure diversity in creating individuals within an initial ensemble. Furthermore, while evolving individuals within the ensemble, it makes use of the negative correlation learning, enabling individual NNs to be trained as accurate as possible while still manage to maintain them as diverse as possible. Therefore, the resulting individuals in the final ensemble are capable of cooperating collectively to achieve better generalization of prediction. The empirical experiment suggest that ERNE is an effective ensemble approach for predicting the Ames test mutagenicity of chemicals.

  4. Knowledge based cluster ensemble for cancer discovery from biomolecular data.

    Science.gov (United States)

    Yu, Zhiwen; Wongb, Hau-San; You, Jane; Yang, Qinmin; Liao, Hongying

    2011-06-01

    The adoption of microarray techniques in biological and medical research provides a new way for cancer diagnosis and treatment. In order to perform successful diagnosis and treatment of cancer, discovering and classifying cancer types correctly is essential. Class discovery is one of the most important tasks in cancer classification using biomolecular data. Most of the existing works adopt single clustering algorithms to perform class discovery from biomolecular data. However, single clustering algorithms have limitations, which include a lack of robustness, stability, and accuracy. In this paper, we propose a new cluster ensemble approach called knowledge based cluster ensemble (KCE) which incorporates the prior knowledge of the data sets into the cluster ensemble framework. Specifically, KCE represents the prior knowledge of a data set in the form of pairwise constraints. Then, the spectral clustering algorithm (SC) is adopted to generate a set of clustering solutions. Next, KCE transforms pairwise constraints into confidence factors for these clustering solutions. After that, a consensus matrix is constructed by considering all the clustering solutions and their corresponding confidence factors. The final clustering result is obtained by partitioning the consensus matrix. Comparison with single clustering algorithms and conventional cluster ensemble approaches, knowledge based cluster ensemble approaches are more robust, stable and accurate. The experiments on cancer data sets show that: 1) KCE works well on these data sets; 2) KCE not only outperforms most of the state-of-the-art single clustering algorithms, but also outperforms most of the state-of-the-art cluster ensemble approaches.

  5. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence.

    Science.gov (United States)

    Kelly, David; Majda, Andrew J; Tong, Xin T

    2015-08-25

    The ensemble Kalman filter and ensemble square root filters are data assimilation methods used to combine high-dimensional, nonlinear dynamical models with observed data. Ensemble methods are indispensable tools in science and engineering and have enjoyed great success in geophysical sciences, because they allow for computationally cheap low-ensemble-state approximation for extremely high-dimensional turbulent forecast models. From a theoretical perspective, the dynamical properties of these methods are poorly understood. One of the central mysteries is the numerical phenomenon known as catastrophic filter divergence, whereby ensemble-state estimates explode to machine infinity, despite the true state remaining in a bounded region. In this article we provide a breakthrough insight into the phenomenon, by introducing a simple and natural forecast model that transparently exhibits catastrophic filter divergence under all ensemble methods and a large set of initializations. For this model, catastrophic filter divergence is not an artifact of numerical instability, but rather a true dynamical property of the filter. The divergence is not only validated numerically but also proven rigorously. The model cleanly illustrates mechanisms that give rise to catastrophic divergence and confirms intuitive accounts of the phenomena given in past literature.

  6. Improving ensemble forecasting with q-norm bred vectors

    Science.gov (United States)

    Pazo, Diego; Lopez, Juan Manuel; Rodriguez, Miguel Angel

    2016-04-01

    Error breeding is a popular and simple method to generate initial perturbations for use in ensemble forecasting that is used for operational purposes in many weather/climate centres worldwide. There is a widespread belief among practitioners that the type of norm used in the periodic normalizations of BVs does not have an effect on the performance of ensemble forecasting systems. However, we have recently reported that BVs constructed with different norms have indeed very different dynamical and spatial properties. In particular, BVs constructed with the 0-norm or geometric norm has nice properties (e.g. enhancement of the ensemble diversity), which in principle render it more adequate to construct ensembles than other norm types like the Euclidean one. These advantages are clearly demonstrated here in a simple experiment of ensemble forecasting for the Lorenz-96 model with ensembles of BVs. Our simple numerical assimilation experiment shows how the increased statistical diversity of geometric BVs leads to improved scores regarding forecasting capabilities as compared with BVs constructed with the standard Euclidean norm.

  7. Hybrid Intrusion Detection Using Ensemble of Classification Methods

    Directory of Open Access Journals (Sweden)

    M.Govindarajan

    2014-01-01

    Full Text Available One of the major developments in machine learning in the past decade is the ensemble method, which finds highly accurate classifier by combining many moderately accurate component classifiers. In this research work, new ensemble classification methods are proposed for homogeneous ensemble classifiers using bagging and heterogeneous ensemble classifiers using arcing classifier and their performances are analyzed in terms of accuracy. A Classifier ensemble is designed using Radial Basis Function (RBF and Support Vector Machine (SVM as base classifiers. The feasibility and the benefits of the proposed approaches are demonstrated by the means of real and benchmark data sets of intrusion detection. The main originality of the proposed approach is based on three main parts: preprocessing phase, classification phase and combining phase. A wide range of comparative experiments are conducted for real and benchmark data sets of intrusion detection. The accuracy of base classifiers is compared with homogeneous and heterogeneous models for data mining problem. The proposed ensemble methods provide significant improvement of accuracy compared to individual classifiers and also heterogeneous models exhibit better results than homogeneous models for real and benchmark data sets of intrusion detection.

  8. Three-model ensemble wind prediction in southern Italy

    Science.gov (United States)

    Torcasio, Rosa Claudia; Federico, Stefano; Calidonna, Claudia Roberta; Avolio, Elenio; Drofa, Oxana; Landi, Tony Christian; Malguzzi, Piero; Buzzi, Andrea; Bonasoni, Paolo

    2016-03-01

    Quality of wind prediction is of great importance since a good wind forecast allows the prediction of available wind power, improving the penetration of renewable energies into the energy market. Here, a 1-year (1 December 2012 to 30 November 2013) three-model ensemble (TME) experiment for wind prediction is considered. The models employed, run operationally at National Research Council - Institute of Atmospheric Sciences and Climate (CNR-ISAC), are RAMS (Regional Atmospheric Modelling System), BOLAM (BOlogna Limited Area Model), and MOLOCH (MOdello LOCale in H coordinates). The area considered for the study is southern Italy and the measurements used for the forecast verification are those of the GTS (Global Telecommunication System). Comparison with observations is made every 3 h up to 48 h of forecast lead time. Results show that the three-model ensemble outperforms the forecast of each individual model. The RMSE improvement compared to the best model is between 22 and 30 %, depending on the season. It is also shown that the three-model ensemble outperforms the IFS (Integrated Forecasting System) of the ECMWF (European Centre for Medium-Range Weather Forecast) for the surface wind forecasts. Notably, the three-model ensemble forecast performs better than each unbiased model, showing the added value of the ensemble technique. Finally, the sensitivity of the three-model ensemble RMSE to the length of the training period is analysed.

  9. PKI Interoperability Based on Online Certificate Validation

    Directory of Open Access Journals (Sweden)

    Dinu Smadu

    2011-03-01

    Full Text Available One of the most important problems related to Public Key Infrastructures is the validation of the digital certificates. Certificate validation services can be based on offline and/or online schemes. Offline schemes have the major disadvantage that they cannot always give an up-to-date response. On the other side, the most used protocol for online validation, the Online Certificate Status Protocol [1], also has its drawbacks. It can only state if a certificate has been revoked or not. RFC 5055 [2] defines a more complex protocol, the Server-based Certificate Validation Protocol (SCVP, capable of building and validating the certification path. To implement a basic functionality of this new protocol, we will start from an existing project, the CADDISK and we will try to implement an OpenSSL module.

  10. EnsembleGASVR: A novel ensemble method for classifying missense single nucleotide polymorphisms

    KAUST Repository

    Rapakoulia, Trisevgeni

    2014-04-26

    Motivation: Single nucleotide polymorphisms (SNPs) are considered the most frequently occurring DNA sequence variations. Several computational methods have been proposed for the classification of missense SNPs to neutral and disease associated. However, existing computational approaches fail to select relevant features by choosing them arbitrarily without sufficient documentation. Moreover, they are limited to the problem ofmissing values, imbalance between the learning datasets and most of them do not support their predictions with confidence scores. Results: To overcome these limitations, a novel ensemble computational methodology is proposed. EnsembleGASVR facilitates a twostep algorithm, which in its first step applies a novel evolutionary embedded algorithm to locate close to optimal Support Vector Regression models. In its second step, these models are combined to extract a universal predictor, which is less prone to overfitting issues, systematizes the rebalancing of the learning sets and uses an internal approach for solving the missing values problem without loss of information. Confidence scores support all the predictions and the model becomes tunable by modifying the classification thresholds. An extensive study was performed for collecting the most relevant features for the problem of classifying SNPs, and a superset of 88 features was constructed. Experimental results show that the proposed framework outperforms well-known algorithms in terms of classification performance in the examined datasets. Finally, the proposed algorithmic framework was able to uncover the significant role of certain features such as the solvent accessibility feature, and the top-scored predictions were further validated by linking them with disease phenotypes. © The Author 2014.

  11. Ensemble Kalman filter versus ensemble smoother for assessing hydraulic conductivity via tracer test data assimilation

    Directory of Open Access Journals (Sweden)

    E. Crestani

    2013-04-01

    Full Text Available Estimating the spatial variability of hydraulic conductivity K in natural aquifers is important for predicting the transport of dissolved compounds. Especially in the nonreactive case, the plume evolution is mainly controlled by the heterogeneity of K. At the local scale, the spatial distribution of K can be inferred by combining the Lagrangian formulation of the transport with a Kalman-filter-based technique and assimilating a sequence of time-lapse concentration C measurements, which, for example, can be evaluated on site through the application of a geophysical method. The objective of this work is to compare the ensemble Kalman filter (EnKF and the ensemble smoother (ES capabilities to retrieve the hydraulic conductivity spatial distribution in a groundwater flow and transport modeling framework. The application refers to a two-dimensional synthetic aquifer in which a tracer test is simulated. Moreover, since Kalman-filter-based methods are optimal only if each of the involved variables fit to a Gaussian probability density function (pdf and since this condition may not be met by some of the flow and transport state variables, issues related to the non-Gaussianity of the variables are analyzed and different transformation of the pdfs are considered in order to evaluate their influence on the performance of the methods. The results show that the EnKF reproduces with good accuracy the hydraulic conductivity field, outperforming the ES regardless of the pdf of the concentrations.

  12. Making calculated energy certificate for choosen building

    OpenAIRE

    Hafner, Rok

    2015-01-01

    The graduation thesis addresses four given energy efficiency certificates for the preschool in Škofja Loka, calculated according to the valid legislation and work methodology. The building in question was built in the seventies of last century and had it's efficiency improved in 2014. The state of the building before improvements has both measured and calculated efficiency certificates made using the KI Energija 2014 program, while the two energy efficiency certificates for the...

  13. Teacher Certification Among Athletic Training Students

    OpenAIRE

    Curtis, Neil

    1995-01-01

    Researchers have reported that athletic training students who earn teacher certification enhance their job marketability. The purpose of this study was to determine the number of athletic training students who pursue teacher certification. A survey was mailed to the directors of the 78 NATA undergraduate programs in 1992. Data from the returned surveys showed that 177 of the 703 expected graduates in 1992 and 148 of the 640 graduates in 1991 pursued teacher certification. The most common teac...

  14. ISO 9001 certification : customer’s perspective

    OpenAIRE

    Matias, Diana; Sampaio, Paulo; Braga, A.C.

    2011-01-01

    Based on our own experience and on the literature review carried out the ISO 9001 research studies have mostly addressed certification issues from the companies point of view, namely companies certification motivations and benefits, benefits evolution over time, barriers to the quality management system implementation, evolution and diffusion of worldwide ISO 9001 certification, the impact on organizational and financial performance and the relation between ISO 9001 and Total Quality Manageme...

  15. Comparing climate change impacts on crops in Belgium based on CMIP3 and EU-ENSEMBLES multi-model ensembles

    Science.gov (United States)

    Vanuytrecht, E.; Raes, D.; Willems, P.; Semenov, M.

    2012-04-01

    Global Circulation Models (GCMs) are sophisticated tools to study the future evolution of the climate. Yet, the coarse scale of GCMs of hundreds of kilometers raises questions about the suitability for agricultural impact assessments. These assessments are often made at field level and require consideration of interactions at sub-GCM grid scale (e.g., elevation-dependent climatic changes). Regional climate models (RCMs) were developed to provide climate projections at a spatial scale of 25-50 km for limited regions, e.g. Europe (Giorgi and Mearns, 1991). Climate projections from GCMs or RCMs are available as multi-model ensembles. These ensembles are based on large data sets of simulations produced by modelling groups worldwide, who performed a set of coordinated climate experiments in which climate models were run for a common set of experiments and various emissions scenarios (Knutti et al., 2010). The use of multi-model ensembles in climate change studies is an important step in quantifying uncertainty in impact predictions, which will underpin more informed decisions for adaptation and mitigation to changing climate (Semenov and Stratonovitch, 2010). The objective of our study was to evaluate the effect of the spatial scale of climate projections on climate change impacts for cereals in Belgium. Climate scenarios were based on two multi-model ensembles, one comprising 15 GCMs of the Coupled Model Intercomparison Project phase 3 (CMIP3; Meehl et al., 2007) with spatial resolution of 200-300 km, the other comprising 9 RCMs of the EU-ENSEMBLES project (van der Linden and Mitchell, 2009) with spatial resolution of 25 km. To be useful for agricultural impact assessments, the projections of GCMs and RCMs were downscaled to the field level. Long series (240 cropping seasons) of local-scale climate scenarios were generated by the LARS-WG weather generator (Semenov et al., 2010) via statistical inference. Crop growth and development were simulated with the Aqua

  16. Formation Of Architectural Ensembles And Complexes Of Historic Towns Of Uzbekistan

    Directory of Open Access Journals (Sweden)

    Manoev Said Bahronovich

    2015-03-01

    Full Text Available Abstract Historical architectural monuments of Uzbekistan attracts attention with their geometrical and compositional harmony. This harmony is one of the fundamentals of Central Asian Islamic architecture which based on decision of Middle Age architects to create ensemble in every case from local ensembles up to whole city ensemble. We can observe this kind of solutions in Ensembles Registrant and Gur Emir in Samarkand in Ensembles Kosh Madrasa and Labi Khovuz in Bukhara in Ensembles Dorus Saodat and Dorut Tilovat in Shakhrisabs in the whole city ensemble of Khiva and many others.

  17. A past discharge assimilation system for ensemble streamflow forecasts over France – Part 2: Impact on the ensemble streamflow forecasts

    Directory of Open Access Journals (Sweden)

    G. Thirel

    2010-04-01

    Full Text Available The use of ensemble streamflow forecasts is developing in the international flood forecasting services. Such systems can provide more accurate forecasts and useful information about the uncertainty of the forecasts, thus improving the assessment of risks. Nevertheless, these systems, like all hydrological forecasts, suffer from errors on initialization or on meteorological data, which lead to hydrological prediction errors. This article, which is the second part of a 2-part article, concerns the impacts of initial states, improved by a streamflow assimilation system, on an ensemble streamflow prediction system over France. An assimilation system was implemented to improve the streamflow analysis of the SAFRAN-ISBA-MODCOU (SIM hydro-meteorological suite, which initializes the ensemble streamflow forecasts at Météo-France. This assimilation system, using the Best Linear Unbiased Estimator (BLUE and modifying the initial soil moisture states, showed an improvement of the streamflow analysis with low soil moisture increments. The final states of this suite were used to initialize the ensemble streamflow forecasts of Météo-France, which are based on the SIM model and use the European Centre for Medium-range Weather Forecasts (ECMWF 10-day Ensemble Prediction System (EPS. Two different configurations of the assimilation system were used in this study: the first with the classical SIM model and the second using improved soil physics in ISBA. The effects of the assimilation system on the ensemble streamflow forecasts were assessed for these two configurations, and a comparison was made with the original (i.e. without data assimilation and without the improved physics ensemble streamflow forecasts. It is shown that the assimilation system improved most of the statistical scores usually computed for the validation of ensemble predictions (RMSE, Brier Skill Score and its decomposition, Ranked Probability Skill Score, False Alarm Rate, etc., especially

  18. Investigating weaknesses in Android certificate security

    Science.gov (United States)

    Krych, Daniel E.; Lange-Maney, Stephen; McDaniel, Patrick; Glodek, William

    2015-05-01

    Android's application market relies on secure certificate generation to establish trust between applications and their users; yet, cryptography is often not a priority for application developers and many fail to take the necessary security precautions. Indeed, there is cause for concern: several recent high-profile studies have observed a pervasive lack of entropy on Web-systems leading to the factorization of private keys.1 Sufficient entropy, or randomness, is essential to generate secure key pairs and combat predictable key generation. In this paper, we analyze the security of Android certificates. We investigate the entropy present in 550,000 Android application certificates using the Quasilinear GCD finding algorithm.1 Our results show that while the lack of entropy does not appear to be as ubiquitous in the mobile markets as on Web-systems, there is substantial reuse of certificates only one third of the certificates in our dataset were unique. In other words, we find that organizations frequently reuse certificates for different applications. While such a practice is acceptable under Google's specifications for a single developer, we find that in some cases the same certificates are used for a myriad of developers, potentially compromising Android's intended trust relationships. Further, we observed duplicate certificates being used by both malicious and non-malicious applications. The top 3 repeated certificates present in our dataset accounted for a total of 11,438 separate APKs. Of these applications, 451, or roughly 4%, were identified as malicious by antivirus services.

  19. Analysis of the green certificate market

    International Nuclear Information System (INIS)

    This report studies the advantages and disadvantages of a separate financial market for the environmental advantages in the production of electricity from renewable energy sources. This market solution is evaluated against other financial systems used to promote the production of green electricity. By starting from a general equilibrium model for the green certificate market, the report discusses how the adaptation in the certificate market is influenced by changes in the market conditions. The certificate market is combined with a quota market for carbon dioxide, with and without international trade with electricity and certificate and market power in the production of electricity from renewable energy sources

  20. DB2 9 Fundamentals Certification Study Guide

    CERN Document Server

    Sanders, Roger E

    2007-01-01

    Starting with the certification process itself and ending with the concept of isolation levels and locking, this guide covers everything needed to know to pass the DB2 9 Fundamentals Certification Exam (Exam 730). The prerequisite for all intermediate and follow-on DB2 certifications, XML usage, basic table creation, a rich set of sample questions, and detailed answers are all included, forming the foundation for understanding the newest version of IBM's flagship database product. Regardless of what future certification path the reader is planning on pursuing, this study guide will chart a cou

  1. 8 CFR 1103.4 - Certifications.

    Science.gov (United States)

    2010-01-01

    ... agricultural worker and legalization cases—(1) General. The Commissioner or the Commissioner's delegate may.... (b) Certification of denials of special agricultural worker and legalization applications....

  2. 77 FR 73334 - Adding International Energy Efficiency (IEE) Certificate to List of Certificates a Recognized...

    Science.gov (United States)

    2012-12-10

    ... SECURITY Coast Guard 46 CFR Part 8 RIN 1625-AB90 Adding International Energy Efficiency (IEE) Certificate... to add the International Energy Efficiency (IEE) Certificate to the list of certificates that a... the Protocol of 1978, has been amended to address energy efficiency for ships, and these...

  3. Reconversion écologique et socialisation des retraites : pour une politique industrielle du XXIe siècle

    Directory of Open Access Journals (Sweden)

    Gilles L. Bourque

    2011-11-01

    Full Text Available Cet article présente une analyse des scénarios possibles au Québec pour assurer la reconversion écologique du secteur des transports collectifs. La réflexion sur l'avenir des politiques industrielles doit en effet intégrer l'impact des changements climatiques et de la réduction de la disponibilité des énergies fossiles. Au Québec, le modèle de développement a toujours intégré la question de l'indépendance énergétique, et plus récemment des énergies renouvelables, à la réflexion sur le modèle de développement. L'apport de la recherche consiste à évaluer, dans une perspective globale pour l'ensemble du secteur et pour le Québec dans son ensemble, les enjeux de l'électrification du transport collectif, autant à l'intérieur des agglomérations que pour le transport entre les pôles régionaux. L'analyse des enjeux de l'électrification du transport collectif porte également sur les modes de financement possibles à l'intérieur du système de retraite au Québec, que ce soit dans le cadre actuel des politiques de placement des régimes de retraite ou encore à travers la création d'outils financiers particuliers comme cela a été fait dans d'autres pays.This article presents a coherent scenario to provide ecological transition of public transport in order to escape from the dependency on non-renewable energy sources. This transition is an important matter for industrial economics and public policy because sectoral level analysis is usually the most effective one. In Québec, the model of development has taken into account for a long time the issue of energetic independence through renewable energy and its impact on industries. This article offers a global evaluation of the costs and financing process for the transition towards electric public transport in large cities and between them. It also shows that it is possible to secure the funds through pension funds investment policy and the creation of green bonds that are

  4. Combining 2-m temperature nowcasting and short range ensemble forecasting

    Directory of Open Access Journals (Sweden)

    A. Kann

    2011-12-01

    Full Text Available During recent years, numerical ensemble prediction systems have become an important tool for estimating the uncertainties of dynamical and physical processes as represented in numerical weather models. The latest generation of limited area ensemble prediction systems (LAM-EPSs allows for probabilistic forecasts at high resolution in both space and time. However, these systems still suffer from systematic deficiencies. Especially for nowcasting (0–6 h applications the ensemble spread is smaller than the actual forecast error. This paper tries to generate probabilistic short range 2-m temperature forecasts by combining a state-of-the-art nowcasting method and a limited area ensemble system, and compares the results with statistical methods. The Integrated Nowcasting Through Comprehensive Analysis (INCA system, which has been in operation at the Central Institute for Meteorology and Geodynamics (ZAMG since 2006 (Haiden et al., 2011, provides short range deterministic forecasts at high temporal (15 min–60 min and spatial (1 km resolution. An INCA Ensemble (INCA-EPS of 2-m temperature forecasts is constructed by applying a dynamical approach, a statistical approach, and a combined dynamic-statistical method. The dynamical method takes uncertainty information (i.e. ensemble variance from the operational limited area ensemble system ALADIN-LAEF (Aire Limitée Adaptation Dynamique Développement InterNational Limited Area Ensemble Forecasting which is running operationally at ZAMG (Wang et al., 2011. The purely statistical method assumes a well-calibrated spread-skill relation and applies ensemble spread according to the skill of the INCA forecast of the most recent past. The combined dynamic-statistical approach adapts the ensemble variance gained from ALADIN-LAEF with non-homogeneous Gaussian regression (NGR which yields a statistical mbox{correction} of the first and second moment (mean bias and dispersion for Gaussian distributed continuous

  5. Protein Ensembles: How Does Nature Harness Thermodynamic Fluctuations for Life? The Diverse Functional Roles of Conformational Ensembles in the Cell.

    Science.gov (United States)

    Wei, Guanghong; Xi, Wenhui; Nussinov, Ruth; Ma, Buyong

    2016-06-01

    All soluble proteins populate conformational ensembles that together constitute the native state. Their fluctuations in water are intrinsic thermodynamic phenomena, and the distributions of the states on the energy landscape are determined by statistical thermodynamics; however, they are optimized to perform their biological functions. In this review we briefly describe advances in free energy landscape studies of protein conformational ensembles. Experimental (nuclear magnetic resonance, small-angle X-ray scattering, single-molecule spectroscopy, and cryo-electron microscopy) and computational (replica-exchange molecular dynamics, metadynamics, and Markov state models) approaches have made great progress in recent years. These address the challenging characterization of the highly flexible and heterogeneous protein ensembles. We focus on structural aspects of protein conformational distributions, from collective motions of single- and multi-domain proteins, intrinsically disordered proteins, to multiprotein complexes. Importantly, we highlight recent studies that illustrate functional adjustment of protein conformational ensembles in the crowded cellular environment. We center on the role of the ensemble in recognition of small- and macro-molecules (protein and RNA/DNA) and emphasize emerging concepts of protein dynamics in enzyme catalysis. Overall, protein ensembles link fundamental physicochemical principles and protein behavior and the cellular network and its regulation. PMID:26807783

  6. Modifications mécaniques et biologiques induites dans des cellules en culture par application locale d'une force contrôlée

    OpenAIRE

    Icard Arcizet, Delphine

    2007-01-01

    Les propriétés mécaniques des cellules adhérentes ont une importance capitale pour l'ensemble de leurs fonctions : division, migration, différenciation, etc. De plus, on sait désormais qu'elles sont très sensibles aux caractéristiques mécaniques de leur substrat, auquel elles sont ancrées par l'intermédiaire des intégrines. Ces récepteurs transmembranaires lient indirectement le cytosquelette d'actine intracellulaire aux protéines de la matrice extracellulaire.Nous avons conçu un dispositif d...

  7. Un modèle intégrateur du capital-client de la marque : une perspective psycho-cognitive

    OpenAIRE

    Czellar, Sandor; Denis, Jean-Emile

    2001-01-01

    L'approche psycho-cognitive du capital-client est exposée après avoir examiné les différents courants de recherche sur la valeur de la marque. Celle-ci constitue actuellement le paradigme dominant. Sur la base des travaux antérieurs, un modèle intégrateur des antécédents et des conséquences du capital-client est proposé. Ce modèle englobe l'ensemble du processus de création du capital-client, de la conception d'une stratégie marketing jusqu'aux conséquences à long terme du capital-client. La ...

  8. La chimie du XVIIe siècle : une question de principes

    Directory of Open Access Journals (Sweden)

    Rémi Franckowiak

    2008-04-01

    Full Text Available Le tournant du XVIIe au XVIIIe siècle est une période décisive pour l’histoire de la chimie qui passe de la reconnaissance institutionnelle à la contestation de son fondement théorique, pour apparaître au final comme la seule partie de la Physique à pouvoir prétendre atteindre la « vérité certaine ». Ce qui se joue alors n’est rien de moins que la redéfinition de ses principes, à savoir son socle de vérités sur lequel s’appuie la science chimique. Cette période est en fait la dernière étape de l’évolution du rapport entre les deux dimensions – théorique et pratique – dans lesquelles se déploie la chimie, qui a vu, par le développement de l’usage des principes dits seconds, l’ensemble des principes chimiques entrainé vers un réalisme empirique, ayant pour effet d’ôter de la chimie toute cohérence théorique. Aussi l’apparition du mécanisme – pas plus celui de Boyle – n’est-il en réalité responsable du bouleversement que connaît la chimie ; elle n’est pas davantage responsable de sa régénération au tout début du XVIIIe siècle. La conscience de la faiblesse théorique de la chimie va devenir pour elle promesse de vigueur théorique sur la base de ce qui représente sa force : l’expérience. À la suite de la perte de ce qui fut certitude, le chimiste devient un être à ré-instruire. Un chimiste tel que Samuel Cottereau Du Clos illustre parfaitement le passage d’une science chimique comme connaissance des principes à une chimie comme science cette fois du vraisemblable.The last decades of 17th century represent a decisive period for the history of Chemistry which switched from institutional recognition to dispute of its theoretical basis, to seem finally, during the very first years of the next century, the only part of Physics being able to claim reaching the “unquestionable truth”. What did happen then is nothing less than the redefinition of principles of Chemistry

  9. 7 CFR 205.400 - General requirements for certification.

    Science.gov (United States)

    2010-01-01

    ... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Certification § 205.400 General requirements for certification. A person seeking to receive or maintain organic certification under...

  10. China Initiates Voluntary Certification of Public Security Products

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Reporters learned from the Certification and Accreditation Administration of China(CNCA)that burglar-proof door became the first batch of voluntary certification product in public security products.China has formally initiated voluntary certification of public security products.

  11. 14 CFR 121.693 - Load manifest: All certificate holders.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Load manifest: All certificate holders. 121... manifest: All certificate holders. The load manifest must contain the following information concerning the... certificate holder....

  12. Un mode de révélation rare de la maladie de Wegener: une myocardite associée a une endocardite fibroblastique

    Science.gov (United States)

    Arous, Salim; Bensahi, Ilham; Noureddine, Malika; Habbal, Rachida

    2016-01-01

    Nous rapportons à travers cette observation le cas rare d'une maladie de Wegener révélée par une myocardite associée à une endocardite fibroblastique. Le patient a été admis initialement dans un tableau d'insuffisance cardiaque globale, avec un trouble du rythme type flutter auriculaire à l'ECG. A l’échocardiographie le ventricule gauche était non dilaté, siège d'une dysfonction sévère, avec un dosage des troponines positif. Une insuffisance rénale sévère a été découverte fortuitement nécessitant une hémodialyse, associée à une anémie inflammatoire confirmée par la férritinémie et le myélogramme. Le dosage des c-ANCA était fortement positif confirmant le diagnostic. La TDM thoracique avait objectivé une pneumopathie basale droite. Après avoir démarré un traitement adapté comprenant une corticothérapie et un traitement immunosuppresseur, l’évolution a été favorable avec normalisation de la fonction systolique du ventricule gauche. Bien que les manifestations cardiaques cliniques évidentes soient rares, l'atteinte cardiaque au cours de la maladie de Wegener est décrite, nécessitant une orientation diagnostic rapide et une connaissance rigoureuse de cette maladie grave. PMID:27279960

  13. On the proper use of Ensembles for Predictive Uncertainty assessment

    Science.gov (United States)

    Todini, Ezio; Coccia, Gabriele; Ortiz, Enrique

    2015-04-01

    Probabilistic forecasting has become popular in the last decades. Hydrological probabilistic forecasts have been based either on uncertainty processors (Krzysztofowic, 1999; Todini, 2004; Todini, 2008) or on ensembles, following meteorological traditional approaches and the establishment of the HEPEX program (http://hepex.irstea.fr. Unfortunately, the direct use of ensembles as a measure of the predictive density is an incorrect practice, because the ensemble measures the spread of the forecast instead of, following the definition of predictive uncertainty, the conditional probability of the future outcome conditional on the forecast. Only few correct approaches are reported in the literature, which correctly use the ensemble to estimate an expected conditional predictive density (Reggiani et al., 2009), similarly to what is done when several predictive models are available as in the BMA (Raftery et al., 2005) or MCP(Todini, 2008; Coccia and Todini, 2011) approaches. A major problem, limiting the correct use of ensembles, is in fact the difficulty of defining the time dependence of the ensemble members, due to the lack of a consistent ranking: in other words, when dealing with multiple models, the ith model remains the ith model regardless to the time of forecast, while this does not happen when dealing with ensemble members, since there is no definition for the ith member of an ensemble. Nonetheless, the MCP approach (Todini, 2008; Coccia and Todini, 2011), essentially based on a multiple regression in the Normal space, can be easily extended to use ensembles to represent the local (in time) smaller or larger conditional predictive uncertainty, as a function of the ensemble spread. This is done by modifying the classical linear regression equations, impliying perfectly observed predictors, to alternative regression equations similar to the Kalman filter ones, allowing for uncertain predictors. In this way, each prediction in time accounts for both the predictive

  14. Coproduction et partage de documentation francophone de qualité sur le prototypage rapide : une activité d’inspiration socioconstructiviste soutenue par les TIC

    Directory of Open Access Journals (Sweden)

    Sylvie Doré

    2004-03-01

    Full Text Available [Français] Le cours « MEC626 - Prototypage rapide » est centré sur une activité d’apprentissage nommée « séminaire » grâce à laquelle des étudiants coproduisent de la documentation francophone de qualité formant une partie importante des notes de cours. D’inspiration socioconstructiviste, cette activité apprend aux étudiants à utiliser des outils et à développer des savoir-faire qui leur seront utiles lors de l’exercice de leur profession. Au total, sept technologies sont mises en œuvre pour soutenir l’activité. Parmi celles-ci, mentionnons une variété de moteurs de recherche utilisés pour trouver l’information pertinente, un logiciel de gestion de notices bibliographiques servant à classifier l’information et à produire une base de données collective et le transfert FTP permettant l’échange de documents et agissant comme vitrine de travaux. Le séminaire permet non seulement aux étudiants de se familiariser avec le contenu du domaine, mais il leur offre également l’occasion de maîtriser un ensemble d’outils et de méthodes exploitant les TIC, et de vivre une expérience à la fois significative et pertinente. [English] The course MEC626 Prototypage rapide is centred around a learning activity called the Seminar, in which students coproduce high-quality French-language documentation that makes up a large part of the course notes. Social-constructivist in inspiration, this activity mobilizes the students to use tools and develop knowhow that will be useful to them in the practice of their profession. In all, seven technologies support the activity. Most noteworthy among them are : a variety of search engines that are used to find relevant information ; a bibliographical management software that is useful for categorizing information and producing a collective database ; and FTP transfer which allows the exchange of documents and serves as a showcase for student assignments. Not only does the Seminar

  15. CNCA and MOFCOM Released Green Market Certification Rules

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Learned from the Certification and Accreditation Administration of the People's Republic of China (CNCA) on 9th June, the Green Market Certification Rules formulated by the Certification and Accreditation Administration of the People's Republic of China and the Ministry of Commerce (MOFCOM) will be formally implemented from the date of June 30. The Rules has defined specific requirements for the certification institutions and certification personnel engaged in the certification of Green Market.

  16. Regionalization of post-processed ensemble runoff forecasts

    Science.gov (United States)

    Olav Skøien, Jon; Bogner, Konrad; Salamon, Peter; Smith, Paul; Pappenberger, Florian

    2016-05-01

    For many years, meteorological models have been run with perturbated initial conditions or parameters to produce ensemble forecasts that are used as a proxy of the uncertainty of the forecasts. However, the ensembles are usually both biased (the mean is systematically too high or too low, compared with the observed weather), and has dispersion errors (the ensemble variance indicates a too low or too high confidence in the forecast, compared with the observed weather). The ensembles are therefore commonly post-processed to correct for these shortcomings. Here we look at one of these techniques, referred to as Ensemble Model Output Statistics (EMOS) (Gneiting et al., 2005). Originally, the post-processing parameters were identified as a fixed set of parameters for a region. The application of our work is the European Flood Awareness System (www.efas.eu" target="_blank">http://www.efas.eu), where a distributed model is run with meteorological ensembles as input. We are therefore dealing with a considerably larger data set than previous analyses. We also want to regionalize the parameters themselves for other locations than the calibration gauges. The post-processing parameters are therefore estimated for each calibration station, but with a spatial penalty for deviations from neighbouring stations, depending on the expected semivariance between the calibration catchment and these stations. The estimated post-processed parameters can then be used for regionalization of the postprocessing parameters also for uncalibrated locations using top-kriging in the rtop-package (Skøien et al., 2006, 2014). We will show results from cross-validation of the methodology and although our interest is mainly in identifying exceedance probabilities for certain return levels, we will also show how the rtop package can be used for creating a set of post-processed ensembles through simulations.

  17. Quantifying Monte Carlo uncertainty in ensemble Kalman filter

    Energy Technology Data Exchange (ETDEWEB)

    Thulin, Kristian; Naevdal, Geir; Skaug, Hans Julius; Aanonsen, Sigurd Ivar

    2009-01-15

    This report is presenting results obtained during Kristian Thulin PhD study, and is a slightly modified form of a paper submitted to SPE Journal. Kristian Thulin did most of his portion of the work while being a PhD student at CIPR, University of Bergen. The ensemble Kalman filter (EnKF) is currently considered one of the most promising methods for conditioning reservoir simulation models to production data. The EnKF is a sequential Monte Carlo method based on a low rank approximation of the system covariance matrix. The posterior probability distribution of model variables may be estimated fram the updated ensemble, but because of the low rank covariance approximation, the updated ensemble members become correlated samples from the posterior distribution. We suggest using multiple EnKF runs, each with smaller ensemble size to obtain truly independent samples from the posterior distribution. This allows a point-wise confidence interval for the posterior cumulative distribution function (CDF) to be constructed. We present a methodology for finding an optimal combination of ensemble batch size (n) and number of EnKF runs (m) while keeping the total number of ensemble members ( m x n) constant. The optimal combination of n and m is found through minimizing the integrated mean square error (MSE) for the CDFs and we choose to define an EnKF run with 10.000 ensemble members as having zero Monte Carlo error. The methodology is tested on a simplistic, synthetic 2D model, but should be applicable also to larger, more realistic models. (author). 12 refs., figs.,tabs

  18. Bayesian Processor of Ensemble for Precipitation Forecasting: A Development Plan

    Science.gov (United States)

    Toth, Z.; Krzysztofowicz, R.

    2006-05-01

    The Bayesian Processor of Ensemble (BPE) is a new, theoretically-based technique for probabilistic forecasting of weather variates. It is a generalization of the Bayesian Processor of Output (BPO) developed by Krzysztofowicz and Maranzano for processing single values of multiple predictors into a posterior distribution function of a predictand. The BPE processes an ensemble of a predictand generated by multiple integrations of a numerical weather prediction (NWP) model, and optimally fuses the ensemble with climatic data in order to quantify uncertainty about the predictand. As is well known, Bayes theorem provides the optimal theoretical framework for fusing information from different sources and for obtaining the posterior distribution function of a predictand. Using a family of such distribution functions, a given raw ensemble can be mapped into a posterior ensemble, which is well calibrated, has maximum informativeness, and preserves the spatio-temporal and cross-variate dependence structure of the NWP output fields. The challenge is to develop and test the BPE suitable for operational forecasting. This talk will present the basic design components of the BPE, along with a discussion of the climatic and training data to be used in its potential application at the National Centers for Environmental Prediction (NCEP). The technique will be tested first on quasi-normally distributed variates and next on precipitation variates. For reasons of economy, the BPE will be applied on the relatively coarse resolution grid corresponding to the ensemble output, and then the posterior ensemble will be downscaled to finer grids such as that of the National Digital Forecast Database (NDFD).

  19. Critical adsorption and critical Casimir forces in the canonical ensemble.

    Science.gov (United States)

    Gross, Markus; Vasilyev, Oleg; Gambassi, Andrea; Dietrich, S

    2016-08-01

    Critical properties of a liquid film between two planar walls are investigated in the canonical ensemble, within which the total number of fluid particles, rather than their chemical potential, is kept constant. The effect of this constraint is analyzed within mean-field theory (MFT) based on a Ginzburg-Landau free-energy functional as well as via Monte Carlo simulations of the three-dimensional Ising model with fixed total magnetization. Within MFT and for finite adsorption strengths at the walls, the thermodynamic properties of the film in the canonical ensemble can be mapped exactly onto a grand canonical ensemble in which the corresponding chemical potential plays the role of the Lagrange multiplier associated with the constraint. However, due to a nonintegrable divergence of the mean-field order parameter profile near a wall, the limit of infinitely strong adsorption turns out to be not well-defined within MFT, because it would necessarily violate the constraint. The critical Casimir force (CCF) acting on the two planar walls of the film is generally found to behave differently in the canonical and grand canonical ensembles. For instance, the canonical CCF in the presence of equal preferential adsorption at the two walls is found to have the opposite sign and a slower decay behavior as a function of the film thickness compared to its grand canonical counterpart. We derive the stress tensor in the canonical ensemble and find that it has the same expression as in the grand canonical case, but with the chemical potential playing the role of the Lagrange multiplier associated with the constraint. The different behavior of the CCF in the two ensembles is rationalized within MFT by showing that, for a prescribed value of the thermodynamic control parameter of the film, i.e., density or chemical potential, the film pressures are identical in the two ensembles, while the corresponding bulk pressures are not. PMID:27627242

  20. Critical adsorption and critical Casimir forces in the canonical ensemble

    Science.gov (United States)

    Gross, Markus; Vasilyev, Oleg; Gambassi, Andrea; Dietrich, S.

    2016-08-01

    Critical properties of a liquid film between two planar walls are investigated in the canonical ensemble, within which the total number of fluid particles, rather than their chemical potential, is kept constant. The effect of this constraint is analyzed within mean-field theory (MFT) based on a Ginzburg-Landau free-energy functional as well as via Monte Carlo simulations of the three-dimensional Ising model with fixed total magnetization. Within MFT and for finite adsorption strengths at the walls, the thermodynamic properties of the film in the canonical ensemble can be mapped exactly onto a grand canonical ensemble in which the corresponding chemical potential plays the role of the Lagrange multiplier associated with the constraint. However, due to a nonintegrable divergence of the mean-field order parameter profile near a wall, the limit of infinitely strong adsorption turns out to be not well-defined within MFT, because it would necessarily violate the constraint. The critical Casimir force (CCF) acting on the two planar walls of the film is generally found to behave differently in the canonical and grand canonical ensembles. For instance, the canonical CCF in the presence of equal preferential adsorption at the two walls is found to have the opposite sign and a slower decay behavior as a function of the film thickness compared to its grand canonical counterpart. We derive the stress tensor in the canonical ensemble and find that it has the same expression as in the grand canonical case, but with the chemical potential playing the role of the Lagrange multiplier associated with the constraint. The different behavior of the CCF in the two ensembles is rationalized within MFT by showing that, for a prescribed value of the thermodynamic control parameter of the film, i.e., density or chemical potential, the film pressures are identical in the two ensembles, while the corresponding bulk pressures are not.

  1. Pour une poétique queer de Rimbaud

    OpenAIRE

    Kramer, Max

    2014-01-01

    La sexologie et les tabous sexuels ont eu une influence énorme sur la poésie de Rimbaud. Ce dernier a conçu plusieurs stratégies queer (particulièrement de métaphores queer) afin d’effectuer des commentaires obliques sur sa sexualité à une époque de plus en plus homophobe. Cet essai soutient que les études queer devraient faire plus attention, et de façon plus systématique, à ces stratégies et mettre fin à un malaise hétéronormatif de longue date caractéristique de la réception de l’œuvre de ...

  2. Géographie des interfaces. Une nouvelle vision des territoires

    Directory of Open Access Journals (Sweden)

    Marie Redon

    2011-07-01

    Full Text Available Littéralement, une interface est une surface de séparation entre deux états distincts de la matière. Le terme, ayant cheminé de la physique à la biologie, et aussi désormais d’usage répandu en informatique. En géographie, l’usage du mot s’est développé dans les années 1980 et peut être défini comme un espace permettant la mise en relation de deux espaces/territoires différents, influencé par des échanges entre l’un et l’autre, et se distinguant par là-même des deux espaces contigus. Intégrant...

  3. Antoine Audouard, Une maison au bord du monde

    OpenAIRE

    Benoist, Jean

    2009-01-01

    La maison de soins palliatifs de Gardanne est devenue depuis quelques années une référence par la qualité de son accueil, de ses soins, de son personnel. Dans ce petit livre, à l’écriture élégante et à la présentation extrêmement vivante, Antoine Audouard en donne un portrait aussi présent que peuvent l’être un beau roman ou un bon reportage, et aussi précis que le serait une excellente étude ethnographique. Il s’agit moins pour lui de décrire que de faire sentir, par des rencontres. Tout se ...

  4. Les nouveaux droits sociaux, une protection contre l’incertitude

    Directory of Open Access Journals (Sweden)

    Michel Messu

    2010-12-01

    Full Text Available Dans cette livraison qui met en forme les analyses que développe Robert Castel depuis quelques années et les inscrit dans une perspective longue d’évolution historique de nos sociétés, il y a plusieurs novations théoriques et conceptuelles dont certaines sont autant de points de discussion tant elles recèlent de présupposés ou d’options analytiques pour le moins problématiques.Le titre La Montée des incertitudes exprime bien en effet, comme le souhaite Robert Castel, une ligne d’analyse des t...

  5. Claude Jean DEVIRIEUX (2007), Pour une communication efficace

    OpenAIRE

    Collette, Karine

    2013-01-01

    L’auteur, journaliste de la radio et de la télévision de Radio-Canada, est un professionnel de la communication de masse. Il propose de réunir les principes fondamentaux de la communication et de les appliquer à quatre formes de communication : la communication interpersonnelle « parce que c’est la plus courante » ; la prise de parole en public ; la communication média « qui est à la fois une communication interpersonnelle et une prise de parole publique » et la communication de crise « qui d...

  6. Harmonisation of wind turbine certification in Europe JOULE project EWTC

    Energy Technology Data Exchange (ETDEWEB)

    Nath, C. [Germanischer Lloyd, Hamburg (Germany); Eriksson, C. [Det Norske Veritas, Hellerup (Denmark); Hulle, F. van [Frans van Hulle, Petten (Netherlands); Skamris, C. [Risoe National Lab., Roskilde (Denmark); Stam, W. [CIWI Holland, Arnheim (Netherlands); Vionis, P. [CRES, Attki (Greece)

    1999-03-01

    Wind turbine certification requirements are currently fairly divers within Europe. Therefore the leading European certification bodies initiated a JOULE project to harmonise the certification procedure on the basis of the current set of IEC/EN 61400 series standards. The paper presents a review of the state of the art of wind turbine certification in European countries and an outline of the sturcture of the project. The main steps of the project are (a) the collection of differences in certification practices by round robin certification of three wind turbine types; (b) assessment of the different certification results and (c) the development of a harmonised certification procedure. (au) EU-JOULE-3. 19 refs.

  7. Recherche en biotechnologie dans une époque de terrorisme

    OpenAIRE

    Akinyoade, Ademola

    2011-01-01

    Peer reviewed This is a review of Biotechnology in An Age of Terrorism. It summarizes the contents and highlights the contributions of the book to the dual use debate and peace scholarship and practice. Recerca biotecnològica en l'era del terrorisme. Investigación en biotecnología en una época de terrorismo. Recherche en biotechnologie dans une époque de terrorisme.

  8. Postface : La gestion des risques naturels est une dynamique

    NARCIS (Netherlands)

    Jaboyedoff, M.; Charriere, M.K.M.; Derron, M.H.; Nicolet, P.; Sudmeier-Rieux, K.

    2013-01-01

    Les risques sont contrôlés par de nombreux facteurs dont, en premier lieu, les dangers, exprimés par leur fréquence (aléa) à une intensité donnée, mais aussi relativement à un fonctionnement de la société. La gestion des risques, liés aux dangers naturels, implique de les évaluer, en premier lieu, e

  9. Une quatrième famille de particules

    CERN Multimedia

    Cline, D

    1988-01-01

    "On connait trois familles de ces particules élémentaires que sont les quarks et les leptons. Des expériences récentes semblent révéler l'existance d'une quatrièm, et la théorie indique que le nombre de familles n'est probablement pas supérieur à cinq" (8 pages)

  10. Verification of the Forecast Errors Based on Ensemble Spread

    Science.gov (United States)

    Vannitsem, S.; Van Schaeybroeck, B.

    2014-12-01

    The use of ensemble prediction systems allows for an uncertainty estimation of the forecast. Most end users do not require all the information contained in an ensemble and prefer the use of a single uncertainty measure. This measure is the ensemble spread which serves to forecast the forecast error. It is however unclear how best the quality of these forecasts can be performed, based on spread and forecast error only. The spread-error verification is intricate for two reasons: First for each probabilistic forecast only one observation is substantiated and second, the spread is not meant to provide an exact prediction for the error. Despite these facts several advances were recently made, all based on traditional deterministic verification of the error forecast. In particular, Grimit and Mass (2007) and Hopson (2014) considered in detail the strengths and weaknesses of the spread-error correlation, while Christensen et al (2014) developed a proper-score extension of the mean squared error. However, due to the strong variance of the error given a certain spread, the error forecast should be preferably considered as probabilistic in nature. In the present work, different probabilistic error models are proposed depending on the spread-error metrics used. Most of these models allow for the discrimination of a perfect forecast from an imperfect one, independent of the underlying ensemble distribution. The new spread-error scores are tested on the ensemble prediction system of the European Centre of Medium-range forecasts (ECMWF) over Europe and Africa. ReferencesChristensen, H. M., Moroz, I. M. and Palmer, T. N., 2014, Evaluation of ensemble forecast uncertainty using a new proper score: application to medium-range and seasonal forecasts. In press, Quarterly Journal of the Royal Meteorological Society. Grimit, E. P., and C. F. Mass, 2007: Measuring the ensemble spread-error relationship with a probabilistic approach: Stochastic ensemble results. Mon. Wea. Rev., 135, 203

  11. Hierarchical Bayes Ensemble Kalman Filter for geophysical data assimilation

    Science.gov (United States)

    Tsyrulnikov, Michael; Rakitko, Alexander

    2016-04-01

    In the Ensemble Kalman Filter (EnKF), the forecast error covariance matrix B is estimated from a sample (ensemble), which inevitably implies a degree of uncertainty. This uncertainty is especially large in high dimensions, where the affordable ensemble size is orders of magnitude less than the dimensionality of the system. Common remedies include ad-hoc devices like variance inflation and covariance localization. The goal of this study is to optimize the account for the inherent uncertainty of the B matrix in EnKF. Following the idea by Myrseth and Omre (2010), we explicitly admit that the B matrix is unknown and random and estimate it along with the state (x) in an optimal hierarchical Bayes analysis scheme. We separate forecast errors into predictability errors (i.e. forecast errors due to uncertainties in the initial data) and model errors (forecast errors due to imperfections in the forecast model) and include the two respective components P and Q of the B matrix into the extended control vector (x,P,Q). Similarly, we break the traditional forecast ensemble into the predictability-error related ensemble and model-error related ensemble. The reason for the separation of model errors from predictability errors is the fundamental difference between the two sources of error. Model error are external (i.e. do not depend on the filter's performance) whereas predictability errors are internal to a filter (i.e. are determined by the filter's behavior). At the analysis step, we specify Inverse Wishart based priors for the random matrices P and Q and conditionally Gaussian prior for the state x. Then, we update the prior distribution of (x,P,Q) using both observation and ensemble data, so that ensemble members are used as generalized observations and ordinary observations are allowed to influence the covariances. We show that for linear dynamics and linear observation operators, conditional Gaussianity of the state is preserved in the course of filtering. At the forecast

  12. « Moderniser les ressources humaines » dans une petite ville française : appropriations et contournements des normes juridiques et gestionnaires

    Directory of Open Access Journals (Sweden)

    Emilie Biland

    2011-12-01

    Full Text Available Observe-t-on, dans les collectivités locales françaises, récemment instituées en laboratoires de la modernisation publique, un recours croissant à des outils traduisant l’influence de savoirs gestionnaires voire de références issues du nouveau management public ? Pour répondre à cette question, cette contribution s’appuie sur une enquête ethnographique réalisée dans une petite ville, qui étudie les transformations des modes de recrutement et de gestion du personnel depuis le milieu des années 1990. Si la ville enquêtée n’est pas coupée des dynamiques qui traversent l’ensemble du marché du travail, l’adoption de tels outils est loin de s’imposer unilatéralement aux employeurs locaux : elle est conditionnée par les dynamiques internes du gouvernement municipal et dépend, en outre, de la chronologie propre à ce segment du marché du travail. On observe aujourd’hui un cumul de normes juridiques et de normes gestionnaires qui délégitiment les recrutements locaux et assistanciels, qui encouragent la convergence des pratiques des employeurs locaux et accentuent la bureaucratisation formelle.

  13. An adaptive additive inflation scheme for Ensemble Kalman Filters

    Science.gov (United States)

    Sommer, Matthias; Janjic, Tijana

    2016-04-01

    Data assimilation for atmospheric dynamics requires an accurate estimate for the uncertainty of the forecast in order to obtain an optimal combination with available observations. This uncertainty has two components, firstly the uncertainty which originates in the the initial condition of that forecast itself and secondly the error of the numerical model used. While the former can be approximated quite successfully with an ensemble of forecasts (an additional sampling error will occur), little is known about the latter. For ensemble data assimilation, ad-hoc methods to address model error include multiplicative and additive inflation schemes, possibly also flow-dependent. The additive schemes rely on samples for the model error e.g. from short-term forecast tendencies or differences of forecasts with varying resolutions. However since these methods work in ensemble space (i.e. act directly on the ensemble perturbations) the sampling error is fixed and can be expected to affect the skill substiantially. In this contribution we show how inflation can be generalized to take into account more degrees of freedom and what improvements for future operational ensemble data assimilation can be expected from this, also in comparison with other inflation schemes.

  14. Ensemble Forecasting of Major Solar Flares -- First Results

    Science.gov (United States)

    Pulkkinen, A. A.; Guerra, J. A.; Uritsky, V. M.

    2015-12-01

    We present the results from the first ensemble prediction model for major solar flares (M and X classes). Using the probabilistic forecasts from three models hosted at the Community Coordinated Modeling Center (NASA-GSFC) and the NOAA forecasts, we developed an ensemble forecast by linearly combining the flaring probabilities from all four methods. Performance-based combination weights were calculated using a Monte-Carlo-type algorithm that applies a decision threshold PthP_{th} to the combined probabilities and maximizing the Heidke Skill Score (HSS). Using the data for 13 recent solar active regions between years 2012 - 2014, we found that linear combination methods can improve the overall probabilistic prediction and improve the categorical prediction for certain values of decision thresholds. Combination weights vary with the applied threshold and none of the tested individual forecasting models seem to provide more accurate predictions than the others for all values of PthP_{th}. According to the maximum values of HSS, a performance-based weights calculated by averaging over the sample, performed similarly to a equally weighted model. The values PthP_{th} for which the ensemble forecast performs the best are 25 % for M-class flares and 15 % for X-class flares. When the human-adjusted probabilities from NOAA are excluded from the ensemble, the ensemble performance in terms of the Heidke score, is reduced.

  15. Quantumness of correlations, quantumness of ensembles and quantum data hiding

    International Nuclear Information System (INIS)

    We study the quantumness of correlations for ensembles of bi- and multi-partite systems and relate it to the task of quantum data hiding. Quantumness is here intended in the sense of minimum average disturbance under local measurements. We consider a very general framework, but focus on local complete von Neumann measurements as the cause of the disturbance, and, later on, on the trace-distance as a quantifier of the disturbance. We discuss connections with entanglement and previously defined notions of quantumness of correlations. We prove that a large class of quantifiers of the quantumness of correlations are entanglement monotones for pure bipartite states. In particular, we define an entanglement of disturbance for pure states, for which we give an analytical expression. Such a measure coincides with negativity and concurrence for the case of two qubits. We compute general bounds on disturbance for both single states and ensembles, and consider several examples, including the uniform Haar ensemble of pure states, and pairs of qubit states. Finally, we show that the notion of ensemble quantumness of correlations is most relevant in quantum data hiding. Indeed, while it is known that entanglement is not necessary for a good quantum data-hiding scheme, we prove that ensemble quantumness of correlations is necessary. (paper)

  16. Ensemble Forecasting of Volcanic Emissions in Hawai’i

    Directory of Open Access Journals (Sweden)

    Andre Kristofer Pattantyus

    2015-03-01

    Full Text Available Deterministic model forecasts do not convey to the end users the forecast uncertainty the models possess as a result of physics parameterizations, simplifications in model representation of physical processes, and errors in initial conditions. This lack of understanding leads to a level of uncertainty in the forecasted value when only a single deterministic model forecast is available. Increasing computational power and parallel software architecture allows multiple simulations to be carried out simultaneously that yield useful measures of model uncertainty that can be derived from ensemble model results. The Hybrid Single Particle Lagrangian Integration Trajectory and Dispersion model has the ability to generate ensemble forecasts. A meteorological ensemble was formed to create probabilistic forecast products and an ensemble mean forecast for volcanic emissions from the Kilauea volcano that impacts the state of Hawai’i. The probabilistic forecast products show uncertainty in pollutant concentrations that are especially useful for decision-making regarding public health. Initial comparison of the ensemble mean forecasts with observations and a single model forecast show improvements in event timing for both sulfur dioxide and sulfate aerosol forecasts.  

  17. 40 CFR 68.185 - Certification.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Certification. 68.185 Section 68.185 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.185 Certification. (a) For Program 1...

  18. 78 FR 28079 - Certificates of Compliance

    Science.gov (United States)

    2013-05-13

    .... 1110.3 would maintain these provisions, with minor grammatical changes, and would add 13 new... may be posted without change, including any personal identifiers, contact information, or other... on ``certificates of compliance,'' also referred to as ``certificates,'' on November 18, 2008 (73...

  19. 29 CFR 570.121 - Age certificates.

    Science.gov (United States)

    2010-07-01

    ... Provisions of the Fair Labor Standards Act of 1938, as Amended Oppressive Child Labor § 570.121 Age... person is above the oppressive child labor age.” An age certificate is a statement of a minor's age... 29 Labor 3 2010-07-01 2010-07-01 false Age certificates. 570.121 Section 570.121 Labor...

  20. 7 CFR 1570.1100 - Drawback certification.

    Science.gov (United States)

    2010-01-01

    ... OF AGRICULTURE EXPORT BONUS PROGRAMS SOAP and COAP Drawback Certification § 1570.1100 Drawback certification. An offer submitted by an exporter to FAS for an export bonus under the SOAP or the COAP must...: “None of the eligible commodity (sunflowerseed oil and/or cottonseed oil) has been or will be used...

  1. 7 CFR 54.24 - Appeal certificates.

    Science.gov (United States)

    2010-01-01

    ... certificate and stating the class, grade, other quality, or compliance of the products as shown by the appeal... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) MEATS, PREPARED MEATS, AND MEAT PRODUCTS (GRADING, CERTIFICATION, AND STANDARDS) Regulations Appeal Service § 54.24...

  2. 14 CFR 13.19 - Certificate action.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Certificate action. 13.19 Section 13.19... INVESTIGATIVE AND ENFORCEMENT PROCEDURES Legal Enforcement Actions § 13.19 Certificate action. (a) Under section... charges or other reasons upon which the Administrator bases the proposed action and, except in...

  3. 27 CFR 26.260 - Certificate.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Certificate. 26.260 Section 26.260 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Port of Entry From the Virgin Islands § 26.260 Certificate. Persons (except tourists) bringing...

  4. Is Halal Certification Process “Green”?

    Directory of Open Access Journals (Sweden)

    Mohd Rizal Razalli

    2012-09-01

    Full Text Available These days, the environmental perspective on operations is becoming more common. In fact, any effort in improving efficiency in the organization is closely related to sustainability of our environment. The Environmental Management System (EMS certification such as ISO 14001 has been accepted as the world standard. In addition to these ISO standards, there are other certifications such as Halal certification. There is no research that investigates the relationship between Halal Certification process and its effect on our environment. Hence, our main research question is that is Halal Certification process can be considered as environmental friendly? In this paper, we argue that Halal Certification also contributes towards green initiatives. We used EDC-UUM as our case study. EDC-UUM is actively seeking the Halal certification from Malaysian authority agency or JAKIM. In this study, we assessed the perception of the EDC-UUM staff on the issue of going green. The findings and implications are discussed in the paper. Keywords: halal certification, hotel operations, sustainability, green

  5. 14 CFR 63.13 - Temporary certificate.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Temporary certificate. 63.13 Section 63.13 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... his application and supplementary documents and the issue of the certificate for which he applied....

  6. 14 CFR 65.13 - Temporary certificate.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Temporary certificate. 65.13 Section 65.13 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... review of his application and supplementary documents and the issue of the certificate and ratings...

  7. Trust Based Certificate Revocation for Secure Routing

    DEFF Research Database (Denmark)

    xmw970, xmw970

    2016-01-01

    Many trust establishment solutions in mobile ad hoc networks (MANETs) rely on public key certificates. Therefore, they should be accompanied by an efficient mechanism for certificate revocation and validation. In order to reduce the hazards from nodes and to enhance the security of network we...

  8. Brief Introduction to Compulsory Product Certification System

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ What is Compulsory Product Certification System? Compulsory Product Certification System is a kind of product qualifying assessment system which implements under laws and regulations by states in order to protect life security of human, animals and plants as well as environmental protection and national security.

  9. 5 CFR 430.404 - Certification criteria.

    Science.gov (United States)

    2010-01-01

    ... MANAGEMENT Performance Appraisal Certification for Pay Purposes § 430.404 Certification criteria. (a) To be... that the performance expectations for senior employees meet the requirements of 5 CFR part 430... against program performance measures, as well as other relevant considerations; and (iii) Pay...

  10. 5 CFR 430.403 - System certification.

    Science.gov (United States)

    2010-01-01

    ....403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERFORMANCE MANAGEMENT Performance Appraisal Certification for Pay Purposes § 430.403 System certification. (a) The performance appraisal system(s) covering senior employees must be certified by OPM, with OMB concurrence,...

  11. 5 CFR 1330.403 - System certification.

    Science.gov (United States)

    2010-01-01

    ... PERSONNEL MANAGEMENT HUMAN RESOURCES MANAGEMENT Performance Appraisal Certification for Pay Purposes § 1330.403 System certification. (a) The performance appraisal system(s) covering senior employees must be... performance appraisal system(s) that meet the criteria. New appraisal systems established under 5 CFR part...

  12. 15 CFR 996.22 - Certification.

    Science.gov (United States)

    2010-01-01

    ... products; and conveys no automatic, direct or indirect NOAA endorsement of any product or service. (c... NOAA HYDROGRAPHIC PRODUCTS AND SERVICES Certification of a Hydrographic Product and Decertification. § 996.22 Certification. (a) A hydrographic product that has passed the compliance tests...

  13. Existe-t-il une sérénité du texte imprimé et de sa lecture ?

    Directory of Open Access Journals (Sweden)

    Lorenzo Soccavo

    2016-10-01

    Full Text Available Ce texte de réflexion a pour objectif de questionner l'éventuelle perte du sentiment de sérénité de la lecture profonde, au fil des mutations des dispositifs et des pratiques de lecture que nous observons depuis quelques années déjà. C'est à une nouvelle grille de lecture du monde que nous devons nous adapter en nous acculturant à de nouvelles pratiques de lecture. Pour faire face les lecteurs du 21e siècle devront être des lecteurs augmentés. Bien loin de toute sérénité, le lecteur deviendrait lui-même une machine à traiter l'information, un dispositif mental apte à simuler et à stimuler une grammaire générative nous donnant accès à plusieurs niveaux de lecture de l’univers. En arrière-fond de cette mutation des dispositifs et des pratiques de lecture, les grands récits mythiques, d'avant les livres, d'avant même l'écriture, irriguent toujours nos imaginaires et notre inconscient collectif. Romans familiaux et romans nationaux ne font toujours que puiser dans le réservoir de ces temps immémoriaux. Algorithmes, métadonnées et big data, ne sont que des expressions contemporaines de forces antédiluviennes, des mots substitués pour désigner en fait des avatars d'anges et de démons. Les mythes agissent comme de véritables hologrammes narratifs (un hologramme étant un ensemble d'informations qui n'ont justement pas besoin d'un support physique pour apparaître.

  14. D'une pratique à une autre : la médiation de la théorie

    OpenAIRE

    Ar Rouz, David

    2005-01-01

    International audience «En «D'une pratique à une autre : la médiation de la théorie», David ar Rouz ens invita a seguir l'evolució que el va emmenar d'una anàlisi de l'autotraducció a una reflexió sobre el paper del traductor i d'altres participants en l'acte de traduir. David ar Rouz comença per posar en qüestió el mite de l'original i la infal·libilitat de l'autotraductor: «S'adone que l'autotraductor és un traductor com els altres, o més ben dit: que el traductor hauria de ser un autor ...

  15. Une vision renouvelée des paradigmes de l'entrepreneuriat : Vers une reconfiguration de la recherche en entrepreneuriat

    OpenAIRE

    Jaziri, Raouf

    2009-01-01

    La présente communication veut proposer un référentiel théorique pour un concept émergent celui de l'"acadépreneuriat" qui n'a pas suscité beaucoup l'intérêt des chercheurs en entrepreneuriat. En fait , nous essayons de mener une réflexion en vue de transposer une logique entrepreneuriale au sein de l'Université. De même, les chercheurs en entrepreneuriat ne cessent de s'interroger perpétuellement sur les fondements théoriques de leur discipline. L'intérêt de cette contribution étant de tente...

  16. Une société et une auberge de notables sous l’Ancien Régime

    OpenAIRE

    Lichtlé, Francis

    2012-01-01

    La Société du Wagkeller de Colmar est l’exemple type de ces sociétés regroupant les notables d’une ville, principalement les membres du Magistrat, du Conseil et leurs invités. Régie par une réglementation particulière, elle est considérée comme étant l’auberge du patriciat local. Elle permet non seulement à ses membres de se réunir entre eux en toute convivialité après les séances du Conseil mais également d’y convier leurs familles pour y célébrer diverses fêtes. Elle ressemble ainsi forteme...

  17. Un modèle de fonctionnement d'une couche d'une architecture de communication

    OpenAIRE

    Nguyen Ba, Thu

    1983-01-01

    Les réseaux informatiques connaissent une expansion rapide à l'heure actuelle. Il devenait nécessaire de faire évoluer l'informatique centralisée vers une informatique distribuée car les systèmes d'informations sont par nature répartis. Mais cette évolution n'a été possible que grâce à des progrès réalisés dans plusieurs domaines : la technologie (micro-électronique, transmission) et les techniques informatiques avancées nécessaires au développement des réseaux (commutation de paquets, archit...

  18. Properties of the Affine Invariant Ensemble Sampler in high dimensions

    CERN Document Server

    Huijser, David; Brewer, Brendon J

    2015-01-01

    We present theoretical and practical properties of the affine-invariant ensemble sampler Markov chain Monte Carlo method. In high dimensions the affine-invariant ensemble sampler shows unusual and undesirable properties. We demonstrate this with an $n$-dimensional correlated Gaussian toy problem with a known mean and covariance structure, and analyse the burn-in period. The burn-in period seems to be short, however upon closer inspection we discover the mean and the variance of the target distribution do not match the expected, known values. This problem becomes greater as $n$ increases. We therefore conclude that the affine-invariant ensemble sampler should be used with caution in high dimensional problems. We also present some theoretical results explaining this behaviour.

  19. A Flexible Approach for the Statistical Visualization of Ensemble Data

    Energy Technology Data Exchange (ETDEWEB)

    Potter, K. [Univ. of Utah, Salt Lake City, UT (United States). SCI Institute; Wilson, A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bremer, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pascucci, V. [Univ. of Utah, Salt Lake City, UT (United States). SCI Institute; Johnson, C. [Univ. of Utah, Salt Lake City, UT (United States). SCI Institute

    2009-09-29

    Scientists are increasingly moving towards ensemble data sets to explore relationships present in dynamic systems. Ensemble data sets combine spatio-temporal simulation results generated using multiple numerical models, sampled input conditions and perturbed parameters. While ensemble data sets are a powerful tool for mitigating uncertainty, they pose significant visualization and analysis challenges due to their complexity. We present a collection of overview and statistical displays linked through a high level of interactivity to provide a framework for gaining key scientific insight into the distribution of the simulation results as well as the uncertainty associated with the data. In contrast to methods that present large amounts of diverse information in a single display, we argue that combining multiple linked statistical displays yields a clearer presentation of the data and facilitates a greater level of visual data analysis. We demonstrate this approach using driving problems from climate modeling and meteorology and discuss generalizations to other fields.

  20. Matrix product purifications for canonical ensembles and quantum number distributions

    Science.gov (United States)

    Barthel, Thomas

    2016-09-01

    Matrix product purifications (MPPs) are a very efficient tool for the simulation of strongly correlated quantum many-body systems at finite temperatures. When a system features symmetries, these can be used to reduce computation costs substantially. It is straightforward to compute an MPP of a grand-canonical ensemble, also when symmetries are exploited. This paper provides and demonstrates methods for the efficient computation of MPPs of canonical ensembles under utilization of symmetries. Furthermore, we present a scheme for the evaluation of global quantum number distributions using matrix product density operators (MPDOs). We provide exact matrix product representations for canonical infinite-temperature states, and discuss how they can be constructed alternatively by applying matrix product operators to vacuum-type states or by using entangler Hamiltonians. A demonstration of the techniques for Heisenberg spin-1 /2 chains explains why the difference in the energy densities of canonical and grand-canonical ensembles decays as 1 /L .

  1. Generalized Hypergeometric Ensembles: Statistical Hypothesis Testing in Complex Networks

    CERN Document Server

    Casiraghi, Giona; Scholtes, Ingo; Schweitzer, Frank

    2016-01-01

    Statistical ensembles define probability spaces of all networks consistent with given aggregate statistics and have become instrumental in the analysis of relational data on networked systems. Their numerical and analytical study provides the foundation for the inference of topological patterns, the definition of network-analytic measures, as well as for model selection and statistical hypothesis testing. Contributing to the foundation of these important data science techniques, in this article we introduce generalized hypergeometric ensembles, a framework of analytically tractable statistical ensembles of finite, directed and weighted networks. This framework can be interpreted as a generalization of the classical configuration model, which is commonly used to randomly generate networks with a given degree sequence or distribution. Our generalization rests on the introduction of dyadic link propensities, which capture the degree-corrected tendencies of pairs of nodes to form edges between each other. Studyin...

  2. Probabilistic Quantitative Precipitation Forecasting Using Ensemble Model Output Statistics

    CERN Document Server

    Scheuerer, Michael

    2013-01-01

    Statistical post-processing of dynamical forecast ensembles is an essential component of weather forecasting. In this article, we present a post-processing method that generates full predictive probability distributions for precipitation accumulations based on ensemble model output statistics (EMOS). We model precipitation amounts by a generalized extreme value distribution that is left-censored at zero. This distribution permits modelling precipitation on the original scale without prior transformation of the data. A closed form expression for its continuous rank probability score can be derived and permits computationally efficient model fitting. We discuss an extension of our approach that incorporates further statistics characterizing the spatial variability of precipitation amounts in the vicinity of the location of interest. The proposed EMOS method is applied to daily 18-h forecasts of 6-h accumulated precipitation over Germany in 2011 using the COSMO-DE ensemble prediction system operated by the Germa...

  3. Purification of an unpolarized spin ensemble into entangled singlet pairs

    CERN Document Server

    Greiner, Johannes N; Wrachtrup, Jörg

    2016-01-01

    Dynamical polarization of nuclear spin ensembles is of central importance for magnetic resonance studies, precision sensing and for applications in quantum information theory. Here we propose a scheme to generate long-lived singlet pairs in an unpolarized nuclear spin ensemble which is dipolar coupled to the electron spins of a Nitrogen Vacancy center in diamond. The quantum mechanical back-action induced by frequent spin-selective readout of the NV centers allows the nuclear spins to pair up into maximally entangled singlet pairs. Counterintuitively, the robustness of the pair formation to dephasing noise improves with increasing size of the spin ensemble. We also show how the paired nuclear spin state allows for enhanced sensing capabilities of NV centers in diamond.

  4. Locally Accessible Information of Multisite Quantum Ensembles Violates Monogamy

    CERN Document Server

    De, Aditi Sen

    2011-01-01

    Locally accessible information is a useful information-theoretic physical quantity of an ensemble of multiparty quantum states. We find it has properties akin to quantum as well as classical correlations of single multiparty quantum states. It satisfies monotonicity under local quantum operations and classical communication. However we show that it does not follow monogamy, an important property usually satisfied by quantum correlations, and actually violates any such relation to the maximal extent. Violation is obtained even for locally indistinguishable, but globally orthogonal, multisite ensembles. The results assert that while single multiparty quantum states are monogamous with respect to their shared quantum correlations, ensembles of multiparty quantum states may not be so. The results have potential implications for quantum communication systems.

  5. Generation of Exotic Quantum States of a Cold Atomic Ensemble

    DEFF Research Database (Denmark)

    Christensen, Stefan Lund

    can be created and characterized. First we consider a spin-squeezed state. This state is generated by performing quantum non-demolition measurements of the atomic population difference. We show a spectroscopically relevant noise reduction of -1.7dB, the ensemble is in a many-body entangled state......Over the last decades quantum effects have become more and more controllable, leading to the implementations of various quantum information protocols. These protocols are all based on utilizing quantum correlation. In this thesis we consider how states of an atomic ensemble with such correlations...... — a nanofiber based light-atom interface. Using a dual-frequency probing method we measure and prepare an ensemble with a sub-Poissonian atom number distribution. This is a first step towards the implementation of more exotic quantum states....

  6. Adaptive calibration of (u,v)‐wind ensemble forecasts

    DEFF Research Database (Denmark)

    Pinson, Pierre

    2012-01-01

    the adaptive calibration of ECMWF ensemble forecasts of (u,v)‐wind at 10 m above ground level over Europe over a three‐year period between December 2006 and December 2009. Substantial improvements in (bivariate) reliability and in various deterministic/probabilistic scores are observed. Finally, the...... sufficient reliability. The original framework introduced here allows for an adaptive bivariate calibration of these ensemble forecasts. The originality of this methodology lies in the fact that calibrated ensembles still consist of a set of (space–time) trajectories, after translation and dilation. In...... parallel, the parameters of the models employed for improving the stochastic properties of the generating processes involved are adaptively and recursively estimated to accommodate smooth changes in the process characteristics and to lower computational costs. The approach is applied and evaluated based on...

  7. Representations and Ensemble Methods for Dynamic Relational Classification

    CERN Document Server

    Rossi, Ryan A

    2011-01-01

    Temporal networks are ubiquitous and evolve over time by the addition, deletion, and changing of links, nodes, and attributes. Although many relational datasets contain temporal information, the majority of existing techniques in relational learning focus on static snapshots and ignore the temporal dynamics. We propose a framework for discovering temporal representations of relational data to increase the accuracy of statistical relational learning algorithms. The temporal relational representations serve as a basis for classification, ensembles, and pattern mining in evolving domains. The framework includes (1) selecting the time-varying relational components (links, attributes, nodes), (2) selecting the temporal granularity, (3) predicting the temporal influence of each time-varying relational component, and (4) choosing the weighted relational classifier. Additionally, we propose temporal ensemble methods that exploit the temporal-dimension of relational data. These ensembles outperform traditional and mor...

  8. Optical properties of indium phosphide nanowire ensembles at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lohn, Andrew J; Onishi, Takehiro; Kobayashi, Nobuhiko P [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California Santa Cruz-NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2010-09-03

    Ensembles that contain two types (zincblende and wurtzite) of indium phosphide nanowires grown on non-single crystalline surfaces were studied by micro-photoluminescence and micro-Raman spectroscopy at various low temperatures. The obtained spectra are discussed with the emphasis on the effects of differing lattice types, geometries, and crystallographic orientations present within an ensemble of nanowires grown on non-single crystalline surfaces. In the photoluminescence spectra, a typical Varshni dependence of band gap energy on temperature was observed for emissions from zincblende nanowires and in the high temperature regime energy transfer from excitonic transitions and band-edge transitions was identified. In contrast, the photoluminescence emissions associated with wurtzite nanowires were rather insensitive to temperature. Raman spectra were collected simultaneously from zincblende and wurtzite nanowires coexisting in an ensemble. Raman peaks of the wurtzite nanowires are interpreted as those related to the zincblende nanowires by a folding of the phonon dispersion.

  9. Quantum teleportation between remote atomic-ensemble quantum memories

    CERN Document Server

    Bao, Xiao-Hui; Li, Che-Ming; Yuan, Zhen-Sheng; Lu, Chao-Yang; Pan, Jian-Wei

    2012-01-01

    Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a "quantum channel", quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of 100 million rubidium atoms and connected by a 150-meter optical fiber. The spinwave state of one atomic ensemble is mapped to a propagating photon, and subjected to Bell-state measurements with another single photon that is entangled with the spinwave state of the other ensemble. Two-photon detection events herald the succe...

  10. Evaluation of LDA Ensembles Classifiers for Brain Computer Interface

    Science.gov (United States)

    Arjona, Cristian; Pentácolo, José; Gareis, Iván; Atum, Yanina; Gentiletti, Gerardo; Acevedo, Rubén; Rufiner, Leonardo

    2011-12-01

    The Brain Computer Interface (BCI) translates brain activity into computer commands. To increase the performance of the BCI, to decode the user intentions it is necessary to get better the feature extraction and classification techniques. In this article the performance of a three linear discriminant analysis (LDA) classifiers ensemble is studied. The system based on ensemble can theoretically achieved better classification results than the individual counterpart, regarding individual classifier generation algorithm and the procedures for combine their outputs. Classic algorithms based on ensembles such as bagging and boosting are discussed here. For the application on BCI, it was concluded that the generated results using ER and AUC as performance index do not give enough information to establish which configuration is better.

  11. Ensembles of detectors for online detection of transient changes

    Science.gov (United States)

    Artemov, Alexey; Burnaev, Evgeny

    2015-12-01

    Classical change-point detection procedures assume a change-point model to be known and a change consisting in establishing a new observations regime, i.e. the change lasts infinitely long. These modeling assumptions contradicts applied problems statements. Therefore, even theoretically optimal statistics in practice very often fail when detecting transient changes online. In this work in order to overcome limitations of classical change-point detection procedures we consider approaches to constructing ensembles of change-point detectors, i.e. algorithms that use many detectors to reliably identify a change-point. We propose a learning paradigm and specific implementations of ensembles for change detection of short-term (transient) changes in observed time series. We demonstrate by means of numerical experiments that the performance of an ensemble is superior to that of the conventional change-point detection procedures.

  12. Enhanced Sampling in the Well-Tempered Ensemble

    Science.gov (United States)

    Bonomi, M.; Parrinello, M.

    2010-05-01

    We introduce the well-tempered ensemble (WTE) which is the biased ensemble sampled by well-tempered metadynamics when the energy is used as collective variable. WTE can be designed so as to have approximately the same average energy as the canonical ensemble but much larger fluctuations. These two properties lead to an extremely fast exploration of phase space. An even greater efficiency is obtained when WTE is combined with parallel tempering. Unbiased Boltzmann averages are computed on the fly by a recently developed reweighting method [M. Bonomi , J. Comput. Chem. 30, 1615 (2009)JCCHDD0192-865110.1002/jcc.21305]. We apply WTE and its parallel tempering variant to the 2d Ising model and to a Gō model of HIV protease, demonstrating in these two representative cases that convergence is accelerated by orders of magnitude.

  13. Circular β ensembles,CMV representation,characteristic polynomials

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this note we first briefly review some recent progress in the study of the circular β ensemble on the unit circle,where β > 0 is a model parameter.In the special cases β = 1,2 and 4,this ensemble describes the joint probability density of eigenvalues of random orthogonal,unitary and sympletic matrices,respectively.For general β,Killip and Nenciu discovered a five-diagonal sparse matrix model,the CMV representation.This representation is new even in the case β = 2;and it has become a powerful tool for studying the circular β ensemble.We then give an elegant derivation for the moment identities of characteristic polynomials via the link with orthogonal polynomials on the unit circle.

  14. Efficient Kernel-Based Ensemble Gaussian Mixture Filtering

    KAUST Repository

    Liu, Bo

    2015-11-11

    We consider the Bayesian filtering problem for data assimilation following the kernel-based ensemble Gaussian-mixture filtering (EnGMF) approach introduced by Anderson and Anderson (1999). In this approach, the posterior distribution of the system state is propagated with the model using the ensemble Monte Carlo method, providing a forecast ensemble that is then used to construct a prior Gaussian-mixture (GM) based on the kernel density estimator. This results in two update steps: a Kalman filter (KF)-like update of the ensemble members and a particle filter (PF)-like update of the weights, followed by a resampling step to start a new forecast cycle. After formulating EnGMF for any observational operator, we analyze the influence of the bandwidth parameter of the kernel function on the covariance of the posterior distribution. We then focus on two aspects: i) the efficient implementation of EnGMF with (relatively) small ensembles, where we propose a new deterministic resampling strategy preserving the first two moments of the posterior GM to limit the sampling error; and ii) the analysis of the effect of the bandwidth parameter on contributions of KF and PF updates and on the weights variance. Numerical results using the Lorenz-96 model are presented to assess the behavior of EnGMF with deterministic resampling, study its sensitivity to different parameters and settings, and evaluate its performance against ensemble KFs. The proposed EnGMF approach with deterministic resampling suggests improved estimates in all tested scenarios, and is shown to require less localization and to be less sensitive to the choice of filtering parameters.

  15. Numerical weather prediction model tuning via ensemble prediction system

    Science.gov (United States)

    Jarvinen, H.; Laine, M.; Ollinaho, P.; Solonen, A.; Haario, H.

    2011-12-01

    This paper discusses a novel approach to tune predictive skill of numerical weather prediction (NWP) models. NWP models contain tunable parameters which appear in parameterizations schemes of sub-grid scale physical processes. Currently, numerical values of these parameters are specified manually. In a recent dual manuscript (QJRMS, revised) we developed a new concept and method for on-line estimation of the NWP model parameters. The EPPES ("Ensemble prediction and parameter estimation system") method requires only minimal changes to the existing operational ensemble prediction infra-structure and it seems very cost-effective because practically no new computations are introduced. The approach provides an algorithmic decision making tool for model parameter optimization in operational NWP. In EPPES, statistical inference about the NWP model tunable parameters is made by (i) generating each member of the ensemble of predictions using different model parameter values, drawn from a proposal distribution, and (ii) feeding-back the relative merits of the parameter values to the proposal distribution, based on evaluation of a suitable likelihood function against verifying observations. In the presentation, the method is first illustrated in low-order numerical tests using a stochastic version of the Lorenz-95 model which effectively emulates the principal features of ensemble prediction systems. The EPPES method correctly detects the unknown and wrongly specified parameters values, and leads to an improved forecast skill. Second, results with an atmospheric general circulation model based ensemble prediction system show that the NWP model tuning capacity of EPPES scales up to realistic models and ensemble prediction systems. Finally, a global top-end NWP model tuning exercise with preliminary results is published.

  16. Ensemble data assimilation for the reconstruction of mantle circulation

    Science.gov (United States)

    Bocher, Marie; Coltice, Nicolas; Fournier, Alexandre; Tackley, Paul

    2016-04-01

    The surface tectonics of the Earth is the result of mantle dynamics. This link between internal and surface dynamics can be used to reconstruct the evolution of mantle circulation. This is classically done by imposing plate tectonics reconstructions as boundary conditions on numerical models of mantle convection. However, this technique does not account for uncertainties in plate tectonics reconstructions and does not allow any dynamical feedback of mantle dynamics on surface tectonics to develop. Mantle convection models are now able to produce surface tectonics comparable to that of the Earth to first order. We capitalize on these convection models to propose a more consistent integration of plate tectonics reconstructions into mantle convection models. For this purpose, we use the ensemble Kalman filter. This method has been developed and successfully applied to meteorology, oceanography and even more recently outer core dynamics. It consists in integrating sequentially a time series of data into a numerical model, starting from an ensemble of possible initial states. The initial ensemble of states is designed to represent an approximation of the probability density function (pdf) of the a priori state of the system. Whenever new observations are available, each member of the ensemble states is corrected considering both the approximated pdf of the state, and the pdf of the new data. Between two observation times, each ensemble member evolution is computed independently, using the convection model. This technique provides at each time an approximation of the pdf of the state of the system, in the form of a finite ensemble of states. We perform synthetic experiments to assess the efficiency of this method for the reconstruction of mantle circulation.

  17. Four-dimensional Localization and the Iterative Ensemble Kalman Smoother

    Science.gov (United States)

    Bocquet, M.

    2015-12-01

    The iterative ensemble Kalman smoother (IEnKS) is a data assimilation method meant for efficiently tracking the state ofnonlinear geophysical models. It combines an ensemble of model states to estimate the errors similarly to the ensemblesquare root Kalman filter, with a 4D-variational analysis performed within the ensemble space. As such it belongs tothe class of ensemble variational methods. Recently introduced 4DEnVar or the 4D-LETKF can be seen as particular casesof the scheme. The IEnKS was shown to outperform 4D-Var, the ensemble Kalman filter (EnKF) and smoother, with low-ordermodels in all investigated dynamical regimes. Like any ensemble method, it could require the use of localization of theanalysis when the state space dimension is high. However, localization for the IEnKS is not as straightforward as forthe EnKF. Indeed, localization needs to be defined across time, and it needs to be as much as possible consistent withthe dynamical flow within the data assimilation variational window. We show that a Liouville equation governs the timeevolution of the localization operator, which is linked to the evolution of the error correlations. It is argued thatits time integration strongly depends on the forecast dynamics. Using either covariance localization or domainlocalization, we propose and test several localization strategies meant to address the issue: (i) a constant and uniformlocalization, (ii) the propagation through the window of a restricted set of dominant modes of the error covariancematrix, (iii) the approximate propagation of the localization operator using model covariant local domains. Theseschemes are illustrated on the one-dimensional Lorenz 40-variable model.

  18. Bred vectors with customizable scale: 'À la carte' ensemble perturbations

    Science.gov (United States)

    Homar Santaner, V.; Stensrud, D. J.

    2009-09-01

    Short-range forecasts of severe weather are one of the most challenging tasks faced by the atmospheric science community. Our persistent failure to generate accurate numerical forecasts of tornadoes, large hail, heavy precipitation or strong wind events is caused by two fundamental aspects of numerical forecast systems: the chaotic nature of the governing equations and the large uncertainties in both the atmospheric state and the models that govern its evolution. Currently, we cope with both sources of error by describing the state of the atmosphere in a probabilistic manner. In this framework, forecasting becomes predicting the probability density function (pdf) of future states, given the pdf of initial states that are compatible with available observations and previous forecasts. This probabilistic perspective is often created by generating ensembles of deterministic predictions that are aimed at sampling the most important sources of uncertainty in the forecasting system. The ensemble generation/sampling strategy is a crucial aspect of their performance and various methods have been proposed. Although global forecasting offices have been using ensembles of perturbed initial conditions for medium-range operational forecasts since 1994, no consensus exists regarding the optimum sampling strategy for high resolution short-range ensemble forecasts with predicting skill in the mesoscale. Bred vectors, however, have been hypothesized to better capture the growing modes in the highly nonlinear mesoscale dynamics of severe episodes than singular vectors or observation perturbations. Yet even this technique is not able to produce enough diversity in the ensembles to accurately and routinely predict extreme phenomena such as severe weather. Thus, we propose a new method to generate ensembles of initial conditions perturbations that is based on the breeding technique. Given a standard bred mode, a set of customized perturbations is derived with specified amplitudes and

  19. FOXP3 ensembles in T-cell regulation.

    Science.gov (United States)

    Li, Bin; Samanta, Arabinda; Song, Xiaomin; Furuuchi, Keiji; Iacono, Kathryn T; Kennedy, Sarah; Katsumata, Makoto; Saouaf, Sandra J; Greene, Mark I

    2006-08-01

    Our recent studies have identified dynamic protein ensembles containing forkhead box protein 3 (FOXP3) that provide insight into the molecular complexity of suppressor T-cell activities, and it is our goal to determine how these ensembles regulate FOXP3's transcriptional activity in vivo. In this review, we summarize our current understanding of how FOXP3 expression is induced and how FOXP3 functions in vivo as a transcriptional regulator by assembling a multisubunit complex involved in histone modification as well as chromatin remodeling. PMID:16903909

  20. A new ensemble model for short term wind power prediction

    DEFF Research Database (Denmark)

    Madsen, Henrik; Albu, Razvan-Daniel; Felea, Ioan;

    2012-01-01

    As the objective of this study, a non-linear ensemble system is used to develop a new model for predicting wind speed in short-term time scale. Short-term wind power prediction becomes an extremely important field of research for the energy sector. Regardless of the recent advancements in the re......-search of prediction models, it was observed that different models have different capabilities and also no single model is suitable under all situations. The idea behind EPS (ensemble prediction systems) is to take advantage of the unique features of each subsystem to detain diverse patterns that exist in the dataset...

  1. ENSEMBLE methods to reconcile disparate national long range dispersion forecasts

    DEFF Research Database (Denmark)

    Mikkelsen, Torben; Galmarini, S.; Bianconi, R.;

    2003-01-01

    and Web-based software evaluation and exchange tools have been created for real-time reconciliation and harmonisation of real-time dispersion forecastsfrom meteorological and emergency centres across Europe during an accident. The new ENSEMBLE software tools is available to participating national....... ENSEMBLE addresses the problem of achieving a common coherent strategy across European national emergency management when national long-range dispersion forecasts differ from one another during an accidentalatmospheric release of radioactive material. A series of new decision-making “ENSEMBLE” procedures...

  2. Normal random matrix ensemble as a growth problem

    OpenAIRE

    Teodorescu, R.; Bettelheim, E.; Agam, O.; Zabrodin, A.; Wiegmann, P.

    2004-01-01

    In general or normal random matrix ensembles, the support of eigenvalues of large size matrices is a planar domain (or several domains) with a sharp boundary. This domain evolves under a change of parameters of the potential and of the size of matrices. The boundary of the support of eigenvalues is a real section of a complex curve. Algebro-geometrical properties of this curve encode physical properties of random matrix ensembles. This curve can be treated as a limit of a spectral curve which...

  3. Molecular Dynamics Simulation of Glass Transition Behavior of Polyimide Ensemble

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of chromophores to the glass transition temperature of polyimide ensemble has been investigated by means of molecular dynamics simulation in conjunction with barrier analysis. Simulated Tg results indicated a good agreement with experimental value. This study showed the MD simulation could estimate the effect of chromophores to the Tg of polyimide ensemble conveniently and an estimation approach method had a surprising deviation of Tg from experiment. At the same time, a polyimide structure with higher barrier energy was designed and validated by MD simulation.

  4. A Brief Tutorial on the Ensemble Kalman Filter

    OpenAIRE

    Mandel, Jan

    2009-01-01

    The ensemble Kalman filter (EnKF) is a recursive filter suitable for problems with a large number of variables, such as discretizations of partial differential equations in geophysical models. The EnKF originated as a version of the Kalman filter for large problems (essentially, the covariance matrix is replaced by the sample covariance), and it is now an important data assimilation component of ensemble forecasting. EnKF is related to the particle filter (in this context, a particle is the s...

  5. Reservoir History Matching Using Ensemble Kalman Filters with Anamorphosis Transforms

    KAUST Repository

    Aman, Beshir M.

    2012-12-01

    This work aims to enhance the Ensemble Kalman Filter performance by transforming the non-Gaussian state variables into Gaussian variables to be a step closer to optimality. This is done by using univariate and multivariate Box-Cox transformation. Some History matching methods such as Kalman filter, particle filter and the ensemble Kalman filter are reviewed and applied to a test case in the reservoir application. The key idea is to apply the transformation before the update step and then transform back after applying the Kalman correction. In general, the results of the multivariate method was promising, despite the fact it over-estimated some variables.

  6. L'enfant et le conflit de loyauté : une forme de maltraitance psychologique

    OpenAIRE

    E. Becker

    2011-01-01

    Resume Violence conjugale, separation conflictuelle et conflit de loyaute sont intimement lies et constituent un terreau d?une forme de maltraitance psychologique envers les enfants. Ceux-ci presentent une symptomatologie diversifiee en lien avec le processus de loyaute clivee. L?article developpe une reflexion a partir des situations familiales/parentales conflictuelles en nette augmentation. Proie d?un chantage affectif, l?enfant connait ineluctablement l?angoisse et la culpabili...

  7. Entrepreneuriat et transmission des PME : une revue de la littérature

    OpenAIRE

    Dominique Bonet Fernandez; Bruno-Laurent Moschetto; Frédéric Teulon

    2014-01-01

    L’entrepreneuriat est une source de richesses et d’emplois. On devient entrepreneur par la création d’une nouvelle entreprise, mais aussi par la reprise d’entreprises qui existent déjà. La question de la transmission des PME n’est pas toujours perçue comme un sujet prioritaire. Cette question a fait l’objet d’une littérature que nous présentons ici.

  8. Description d’une espèce nouvelle de Lebioderus de Sumatra

    NARCIS (Netherlands)

    Gestro, R.

    1901-01-01

    Le genre Lebioderus était représenté jusqu’à présent par quatre espèces, dont deux de Java (Goryi Westw. et javanus Dohrn), une de Bornéo Candezei Dohrn) et une de Malacca Percheronii Westw.). Mr. Ritsema vient de m’en communiquer une cinquième, provenant de Sumatra, qui diffère notablement des préc

  9. Optimistaion énergétique d'un ensemble industriel Energy Optimization of an Industrial Installation

    Directory of Open Access Journals (Sweden)

    Raimbault C.

    2006-11-01

    Full Text Available Cet article porte sur la mise au point d'une méthode d'optimisation du système de production d'utilités d'un ensemble industriel et l'étude de dispositifs destinés à économiser l'énergie. Le programme d'optimisation fait appel à la programmation linéaire. Un programme générateur de matrice et un programme de traduction des résultats ont été mis au point. On dispose ainsi d'un programme d'optimisation adapté à tout système de production d'utilités. Différents dispositifs permettant d'économiser l'énergie ont été étudiés. L'étude a porté, d'une part, sur des dispositifs classiques tels que les dispositifs de récupération de chaleur sur les fumées et, d'autre part, sur des dispositifs nouveaux. Des solutions nouvelles ont été recherchées dans deux domaines qui sont apparus essentiels : production combinée de travail et de chaleur et valorisation de calories à bas niveau. Enfin la méthode d'optimisation a été appliquée au cas d'une raffinerie réelle dont l'étude avait été effectuée récemment. L'optimisation sur une base économique a permis de dégager une économie de 9,3 % sur la consommation d'énergie, mais a surtout démontré les larges possibilités de la méthode dans son application à un cas concret. This article describes the development of a method for optimizing utilities production systems for on industrial installation and the study of energy-saving systems. The optimization program makes use of linear programming. A matrix-generating program and a result-translating program were developed. The result is an optimization program suited for any utilities production system. Different energy-saving systems were examined, including conventional systems such as heat-recovery devices as well as new systems. New solutions were sought for in two fields which appear essential, i. e. the combined production of work and heat and the valorization of low-level calories. The optimization method was

  10. Maintenance of Certification for Radiation Oncology

    International Nuclear Information System (INIS)

    Maintenance of Certification (MOC) recognizes that in addition to medical knowledge, several essential elements involved in delivering quality care must be developed and maintained throughout one's career. The MOC process is designed to facilitate and document professional development of American Board of Radiology (ABR) diplomates in the essential elements of quality care in Radiation Oncology and Radiologic Physics. ABR MOC has been developed in accord with guidelines of the American Board of Medical Specialties. All Radiation Oncology certificates issued since 1995 are 10-year, time-limited certificates; diplomates with time-limited certificates who wish to maintain specialty certification must complete specific requirements of the American Board of Radiology MOC program. Diplomates with lifelong certificates are not required to participate but are strongly encouraged to do so. Maintenance of Certification is based on documentation of participation in the four components of MOC: (1) professional standing, (2) lifelong learning and self-assessment, (3) cognitive expertise, and (4) performance in practice. Through these components, MOC addresses six competencies-medical knowledge, patient care, interpersonal and communication skills, professionalism, practice-based learning and improvement, and systems-based practice. Details of requirements for components 1, 2, and 3 of MOC are outlined along with aspects of the fourth component currently under development

  11. Création d’applications mobiles via une application Java.

    OpenAIRE

    KAID SLIMANE, Imane; GHEMBAZA, Hayat

    2015-01-01

    Au cours de ce modeste travail, nous avions comme objectif principal de réaliser une application JAVA Desktop en respectant l'hiérarchie de l'approche IDM. La particularité de notre travail était dans la manière d’établir une liaison entre l'abstraction de l'ingénierie dirigé par les modèles et de la concrétisé en une application. L’objectif principal est le développement d’une application qui permet aux « utilisateurs ordinaires » de gé...

  12. Une nouvelle approche de la relation vision-commande en robotique

    OpenAIRE

    Espiau, Bernard; Chaumette, François; Rives, Patrick

    1990-01-01

    Ce rapport presente les concepts et les resultats relatifs a une nouvelle approche de la commande referencee vision en robotique. L'idee de base consiste a considerer un systeme de vision comme un capteur particulier associe a une tache, et insere dans une boucle de commande. Une fois effectuee l'etape necessaire de modelisation, la problematique ainsi posee ressort alors de l'automatique, et met en avant des questions naturelles de stabilite et de robustesse. Ce rapport est structure comme s...

  13. Hydrogen adsorption on bimetallic PdAu(111) surface alloys:minimum adsorption ensemble, ligand and ensemble effects, and ensemble confinement

    OpenAIRE

    Takehiro, Naoki; Liu, Ping; Bergbreiter, Andreas; K. Nørskov, Jens; Behm, R. Juergen

    2014-01-01

    The adsorption of hydrogen on structurally well defined PdAu-Pd(111) monolayer surface alloys was investigated in a combined experimental and theoretical study, aiming at a quantitative understanding of the adsorption and desorption properties of individual PdAu nanostructures. Combining the structural information obtained by high resolution scanning tunneling microscopy (STM), in particular on the abundance of specific adsorption ensembles at different Pd surface concentrations, with informa...

  14. 14 CFR 63.15 - Duration of certificates.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Duration of certificates. 63.15 Section 63...) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS General § 63.15 Duration of certificates. (a... month in which the certificate was issued or renewed. However, the holder may exercise the privileges...

  15. 77 FR 37385 - Export Trade Certificate of Review

    Science.gov (United States)

    2012-06-21

    ... International Trade Administration Export Trade Certificate of Review ACTION: Notice of Application for an Export Trade Certificate of Review Colombia Poultry Export Quota, Inc. (COLOM-PEQ). SUMMARY: The Office... received an application for an Export Trade Certificate of Review (``Certificate''). This notice...

  16. 29 CFR 570.12 - Revoked certificates of age.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Revoked certificates of age. 570.12 Section 570.12 Labor... REGULATIONS, ORDERS AND STATEMENTS OF INTERPRETATION Certificates of Age § 570.12 Revoked certificates of age. A certificate which has been revoked as proof of age under the Act shall be of no force and...

  17. 15 CFR 325.10 - Modifying or revoking a certificate.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Modifying or revoking a certificate... CERTIFICATES OF REVIEW § 325.10 Modifying or revoking a certificate. (a) Action subject to modification or revocation. The Secretary shall revoke a certificate, in whole or in part, or modify it, as the Secretary...

  18. 40 CFR 90.106 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 90.106... Standards and Certification Provisions § 90.106 Certificate of conformity. (a)(1) Except as provided in § 90... certificate of conformity covering such engines; however, engines manufactured during an annual...

  19. 40 CFR 91.106 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 91.106... Provisions § 91.106 Certificate of conformity. (a) Every manufacturer of a new marine SI engine produced... obtain a certificate of conformity covering each engine family. The certificate of conformity must...

  20. 40 CFR 89.105 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 89.105... and Certification Provisions § 89.105 Certificate of conformity. Every manufacturer of a new nonroad compression-ignition engine must obtain a certificate of conformity covering the engine family, as...