WorldWideScience

Sample records for certification ensemble une

  1. Structure fractale tridimensionnelle avec une transformation conforme 1/O dans l'ensemble des Octonions -section tridimensionnelle-

    OpenAIRE

    Colonna, Jean-François

    2014-01-01

    Tridimensional fractal structure with a 1/O conformal transformation in the Octonionic space -tridimensional cross-section- (Structure fractale tridimensionnelle avec une transformation conforme 1/O dans l'ensemble des Octonions -section tridimensionnelle-)

  2. 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...

  3. L’élaboration collective de cartes mentales, une démarche didactique structurante pour l’apprentissage du vivre-ensemble à l’école

    OpenAIRE

    Marsollier, Christophe

    2013-01-01

    Devant le développement des incivilités et de la violence, ces vingt dernières années, l’apprentissage du vivre-ensemble est devenu une priorité. Cinq piliers de compétences entrent en jeu dans cet apprentissage complexe. Nous appuyant sur les conceptions socioconstructivistes selon lesquelles la pratique de débats démocratiques contribue à la construction du jugement moral chez l’enfant et l’adolescent (Piaget, 1932, Xypas, 2003), nous montrons comment, à la lumière d’analyses de pratiques c...

  4. Certificates.

    Science.gov (United States)

    Fry, F

    1994-06-01

    The Concise Oxford English Dictionary defines 'dilemma' as "an argument forcing one to choose one of two alternatives both unfavourable to him (or her)". This is situation that frequently confronts the general practitioner. In this article a personal solution to the problem of 'certificates' is presented. Not every one will necessarily agree with the solutions presented and some may find them unacceptable, or have better solutions. The author warmly welcomes correspondence, either personal, or in the form of Letters to the Editor, as this is a subject in which consensus decisions are important. PMID:8053842

  5. 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...

  6. Ensembl 2012.

    Science.gov (United States)

    Flicek, Paul; Amode, M Ridwan; Barrell, Daniel; Beal, Kathryn; Brent, Simon; Carvalho-Silva, Denise; Clapham, Peter; Coates, Guy; Fairley, Susan; Fitzgerald, Stephen; Gil, Laurent; Gordon, Leo; Hendrix, Maurice; Hourlier, Thibaut; Johnson, Nathan; Kähäri, Andreas K; Keefe, Damian; Keenan, Stephen; Kinsella, Rhoda; Komorowska, Monika; Koscielny, Gautier; Kulesha, Eugene; Larsson, Pontus; Longden, Ian; McLaren, William; Muffato, Matthieu; Overduin, Bert; Pignatelli, Miguel; Pritchard, Bethan; Riat, Harpreet Singh; Ritchie, Graham R S; Ruffier, Magali; Schuster, Michael; Sobral, Daniel; Tang, Y Amy; Taylor, Kieron; Trevanion, Stephen; Vandrovcova, Jana; White, Simon; Wilson, Mark; Wilder, Steven P; Aken, Bronwen L; Birney, Ewan; Cunningham, Fiona; Dunham, Ian; Durbin, Richard; Fernández-Suarez, Xosé M; Harrow, Jennifer; Herrero, Javier; Hubbard, Tim J P; Parker, Anne; Proctor, Glenn; Spudich, Giulietta; Vogel, Jan; Yates, Andy; Zadissa, Amonida; Searle, Stephen M J

    2012-01-01

    The Ensembl project (http://www.ensembl.org) provides genome resources for chordate genomes with a particular focus on human genome data as well as data for key model organisms such as mouse, rat and zebrafish. Five additional species were added in the last year including gibbon (Nomascus leucogenys) and Tasmanian devil (Sarcophilus harrisii) bringing the total number of supported species to 61 as of Ensembl release 64 (September 2011). Of these, 55 species appear on the main Ensembl website and six species are provided on the Ensembl preview site (Pre!Ensembl; http://pre.ensembl.org) with preliminary support. The past year has also seen improvements across the project. PMID:22086963

  7. Ensembl 2012

    OpenAIRE

    Flicek, Paul; Amode, M. Ridwan; Barrell, Daniel; Beal, Kathryn; Brent, Simon; Carvalho-Silva, Denise; Clapham, Peter; Coates, Guy; Fairley, Susan; Fitzgerald, Stephen; Gil, Laurent; Gordon, Leo; Hendrix, Maurice; Hourlier, Thibaut; Johnson, Nathan

    2011-01-01

    The Ensembl project (http://www.ensembl.org) provides genome resources for chordate genomes with a particular focus on human genome data as well as data for key model organisms such as mouse, rat and zebrafish. Five additional species were added in the last year including gibbon (Nomascus leucogenys) and Tasmanian devil (Sarcophilus harrisii) bringing the total number of supported species to 61 as of Ensembl release 64 (September 2011). Of these, 55 species appear on the main Ensembl website ...

  8. 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

  9. 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

  10. 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

  11. John Dewey, Une foi commune

    OpenAIRE

    Lafargue de Grangeneuve, Loïc

    2014-01-01

    Longtemps méconnu en France, le philosophe pragmatiste américain John Dewey figure aujourd’hui en bonne place parmi les théoriciens du politique, notamment en raison de sa conception du public. La parution d’Une foi commune s’inscrit donc dans ce contexte de découverte tardive et encore inachevée d’une œuvre importante, qui interroge les fondements du politique. Ce livre est en fait un ensemble de trois textes dont l’origine est une série de conférences prononcées par Dewey à l’université de ...

  12. 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...

  13. 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...

  14. 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...

  15. Emergence d'une capitale, Brasilia

    OpenAIRE

    Heuzé, Claire

    1986-01-01

    L'idée de la création d'une nouvelle capitale située au centre géographique du pays, et symbole de l'expansion du Brésil vers l'Ouest, est apparue bien avant l'inauguration de Brasilia par J. Kubitschek en 1960. Brasilia correspondait à une volonté politique de mise en valeur de l'intérieur du pays et d'approfondissement de l'unité nationale. Le projet de Lucio Costa prévoyait pour 1980 une population de 500 000 habitants, concentrée dans un ensemble urbain, le "Plan Pilote", où toutes les ca...

  16. Ensemble clustering in deterministic ensemble Kalman filters

    Directory of Open Access Journals (Sweden)

    Javier Amezcua

    2012-07-01

    Full Text Available Ensemble clustering (EC can arise in data assimilation with ensemble square root filters (EnSRFs using non-linear models: an M-member ensemble splits into a single outlier and a cluster of M–1 members. The stochastic Ensemble Kalman Filter does not present this problem. Modifications to the EnSRFs by a periodic resampling of the ensemble through random rotations have been proposed to address it. We introduce a metric to quantify the presence of EC and present evidence to dispel the notion that EC leads to filter failure. Starting from a univariate model, we show that EC is not a permanent but transient phenomenon; it occurs intermittently in non-linear models. We perform a series of data assimilation experiments using a standard EnSRF and a modified EnSRF by a resampling though random rotations. The modified EnSRF thus alleviates issues associated with EC at the cost of traceability of individual ensemble trajectories and cannot use some of algorithms that enhance performance of standard EnSRF. In the non-linear regimes of low-dimensional models, the analysis root mean square error of the standard EnSRF slowly grows with ensemble size if the size is larger than the dimension of the model state. However, we do not observe this problem in a more complex model that uses an ensemble size much smaller than the dimension of the model state, along with inflation and localisation. Overall, we find that transient EC does not handicap the performance of the standard EnSRF.

  17. 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,...

  18. Morphing ensemble Kalman filters

    OpenAIRE

    Beezley, Jonathan D.; Mandel, Jan

    2008-01-01

    A new type of ensemble filter is proposed, which combines an ensemble Kalman filter (EnKF) with the ideas of morphing and registration from image processing. This results in filters suitable for non-linear problems whose solutions exhibit moving coherent features, such as thin interfaces in wildfire modelling. The ensemble members are represented as the composition of one common state with a spatial transformation, called registration mapping, plus a residual. A fully automatic registration m...

  19. Morphing Ensemble Kalman Filters

    OpenAIRE

    Beezley, Jonathan D.; Mandel, Jan

    2007-01-01

    A new type of ensemble filter is proposed, which combines an ensemble Kalman filter (EnKF) with the ideas of morphing and registration from image processing. This results in filters suitable for nonlinear problems whose solutions exhibit moving coherent features, such as thin interfaces in wildfire modeling. The ensemble members are represented as the composition of one common state with a spatial transformation, called registration mapping, plus a residual. A fully automatic registration met...

  20. Une exposition en blanc

    Directory of Open Access Journals (Sweden)

    Sophie Lévy

    2006-03-01

    Full Text Available Cette présentation est celle d’une exposition qui n’existe pas sur l’importance du blanc dans la peinture moderne américaine, et des enjeux historiques et théoriques qui pourraient la soutenir. Il est toujours difficile de parler d’une exposition qui n’existe pas, c’est‑à‑dire essayer de donner une structure verbale à un exercice visuel, et phénoménologique sans corps. L’expérience, déjà tentée, permet néanmoins de clarifier pour soi‑même le sens du projet et de mesurer une réception possible...

  1. 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.

  2. Towards Intelligent Ensembles

    Czech Academy of Sciences Publication Activity Database

    Bureš, Tomáš; Krijt, F.; Plášil, F.; Hnětynka, P.; Jiráček, Z.

    New York,: ACM, 2015, Article No. 17. ISBN 978-1-4503-3393-1. [ECSAW '15. European Conference on Software Architecture Workshops. Dubrovnik (HR), 07.09.2015-08.09.2015] Institutional support: RVO:67985807 Keywords : distributed coordination * architectural adaptation * ensemble-based component systems * component model * emergent architecture * component ensembles * autonomic systems Subject RIV: JC - Computer Hardware ; Software

  3. 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

  4. 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...

  5. 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...

  6. 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.

  7. Ensembles on Random Patches

    OpenAIRE

    Louppe, Gilles; Geurts, Pierre

    2012-01-01

    In this paper, we consider supervised learning under the assumption that the available memory is small compared to the dataset size. This general framework is relevant in the context of big data, distributed databases and embedded systems. We investigate a very simple, yet effective, ensemble framework that builds each individual model of the ensemble from a random patch of data obtained by drawing random subsets of both instances and features from the whole dataset. We carry out an extensive...

  8. Trainer certification

    International Nuclear Information System (INIS)

    A DOE Technical Safety Appraisal in October 1986 found that training at the Portsmouth Gaseous Diffusion Plant was fragmented and lacked uniformity. Training was localized in departments and was more often handled by line supervisors, etc. - with no certification. The Trainer Certification Program has provided the means for applying standard guidelines to ensure that training is designed, applied, and evaluated in a consistent, effective, and efficient manner. The program is in a state of substantial change and a target date for compliance is set for 1989. Trainer certification will provide both current and future resources to ensure consistent and effective training. 22 figures

  9. Climate certificates

    International Nuclear Information System (INIS)

    Reduced emissions of climate gases at the lowest cost require international cooperation in order to ensure that the most cost-efficient measures are taken. A market for emission rights is one way of achieving this. However, creating the right conditions for such a market to operate requires an unambiguous definition of the product to be traded. In this PM, the Swedish Power Association sketches out how such a product could be defined, and how a market for the resulting unambiguously defined product could be operated internationally, in parallel with other markets for energy products. Trade in climate certificates could become a joint EU approach to achieving common results within the field of climate policy. The main features of the proposal are as follows: Electricity producers would be allowed to issue climate certificates for electricity produced without climate-affecting emissions, e.g. in wind power plants. 1 kWh of electricity produced without emissions would entitle the utility to issue a climate certificate for 1 kWh. Electricity from power stations having low emissions, e.g. modern natural gas-fired plants, would entitle the utility to issue certificates in proportion to how much lower their emissions were in comparison with those from conventional coal-fired power stations. The number of certificates would be reduced by an individual coefficient, related directly to the quantity of climate-affecting emissions from the plant concerned. They would be traded and noted on markets in the various member countries. The certificates would not be nationally restricted, but could be traded across borders. Exchanges would be authorised by national authorities, in accordance with overall EU directives. These authorised exchanges would act as certification bodies, checking that certificates had been properly issued in accordance with a corresponding volume of electricity production. Electricity and certificates could be purchased from different suppliers. The

  10. Just Certification

    OpenAIRE

    Diaz Piedregal, Virginie

    2009-01-01

    Through the justice principles –equality, time, status, need, efficiency and worth– developed by Jon Elster, we show in this article how fair trade certification for producers is legitimatised by stakeholders. Based on a field investigation with coffee growers in Peru, Ecuador and Bolivia and with fair trade organisations in the North (Max Havelaar/FLO, Andines and Artisans du Monde), the analysis firstly reviews just certification according to the impersonal criteria of “mechanical” justice,...

  11. The semantic similarity ensemble

    Directory of Open Access Journals (Sweden)

    Andrea Ballatore

    2013-12-01

    Full Text Available Computational measures of semantic similarity between geographic terms provide valuable support across geographic information retrieval, data mining, and information integration. To date, a wide variety of approaches to geo-semantic similarity have been devised. A judgment of similarity is not intrinsically right or wrong, but obtains a certain degree of cognitive plausibility, depending on how closely it mimics human behavior. Thus selecting the most appropriate measure for a specific task is a significant challenge. To address this issue, we make an analogy between computational similarity measures and soliciting domain expert opinions, which incorporate a subjective set of beliefs, perceptions, hypotheses, and epistemic biases. Following this analogy, we define the semantic similarity ensemble (SSE as a composition of different similarity measures, acting as a panel of experts having to reach a decision on the semantic similarity of a set of geographic terms. The approach is evaluated in comparison to human judgments, and results indicate that an SSE performs better than the average of its parts. Although the best member tends to outperform the ensemble, all ensembles outperform the average performance of each ensemble's member. Hence, in contexts where the best measure is unknown, the ensemble provides a more cognitively plausible approach.

  12. 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.

  13. 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

  14. Continuing certification

    International Nuclear Information System (INIS)

    Northeast Utilities completed the initial certification milestone for its Millstone 2 simulator in June of 1989. NU intends to reach that milestone on its other 3 simulators by the 3rd quarter of 1990. This paper will provide an overview of the resources (manpower, simulator time, etc.) that NU has allocated to maintain its simulators ANS-3.5 compliant, i.e., certified. NU's plan for ensuring on-going compliance to the regulatory requirements is centered around its formal, proceduralized Certification Program which addresses, as one of its main functions, simulator configuration management. Simulator configuration management will remain an on-going commitment requiring considerable attention and allocation of resources throughout the life of the simulator. This paper will describe NU's experience with this phase of the certification process for the Millstone 2 simulator, namely: updating of the design data base, implementation of plant design changes and resolution of simulator deficiencies, performance testing (including operability testing), and documentation

  15. 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....

  16. Réseau acoustique ad-hoc de transfert de données dans un milieu formé de matériau poreux et d'une phase fluide : Demande de brevet n°10 52050

    OpenAIRE

    Ghis, Anne; Lebental, Bérengère

    2010-01-01

    Communications au sein d'un ensemble de dispositifs dispersés dans un milieu polyphasique, utilisant une modulation de la pression de la phase fluide du milieu environnant pour transmettre les informations.

  17. Une plate-forme XML pour représenter des documents et leur contenu pour la mise en oeuvre du Web sémantique

    OpenAIRE

    Al Hulou, Rim; Corby, Olivier; Dieng-Kuntz, Rose; Euzenat, Jérôme; Medina Ramirez, Carolina; Napoli, Amedeo; Troncy, Raphael

    2002-01-01

    Les documents accessibles à partir du Web ou d'une base documentaire quelconque constituent une source considérable de connaissances. Cet article présente le projet ESCRIRE, dont un des objectifs est de construire une plate-forme XML associée à un système de représentation des connaissances, pour annoter et consulter des documents, en tirant parti d'une ontologie du domaine construite à partir du contenu des documents. L'ensemble de ces fonctionnalités constitue l'un des préalables à la mise ...

  18. Ré-ingénierie d'une plate-forme fondée sur la modélisation d'un processus global de FOAD

    OpenAIRE

    Oubahssi, Lahcen; Grandbastien, Monique; Claës, Gérard

    2004-01-01

    Les fournisseurs de plates-formes pour la formation en ligne doivent pouvoir adapter leur offre aux nouveaux besoins des acteurs et aux évolutions technologiques tout en exploitant un existant. Un processus de réingénierie de logiciel existant, aboutissant à une architecture à base de composants réutilisables et interopérables est proposé dans cet article. Il comprend une spécification fonctionnelle couvrant l'ensemble du cycle d'une FOAD et une décomposition en composants implantant les fonc...

  19. Le diabète, une épidémie silencieuse

    OpenAIRE

    Amar, Jacques

    2013-01-01

    Le diabète, une épidémie silencieuse constitue une tentative originale de rendre compte dans une perspective pluri-disciplinaire de ce que l’on pourrait qualifier de fait social objectif : la propagation d’une maladie dont les effets ne sont pas ressentis immédiatement à un ensemble de personnes de plus en plus étendus. Les chiffres évoqués sont en effet éloquents : 370 millions de personnes de par le monde, dont 3 millions en France, seraient atteint de diabète. L’ouvrage présente, entre aut...

  20. 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...

  1. Kingston Soundpainting Ensemble

    OpenAIRE

    Minors, Helen Julia

    2012-01-01

    This performance is designed to introduce teachers and school musicians to this live multidisciplinary live composing sign language. Led by Dr. Helen Julia Minors (soundpainter, trumpet, voice), the Kingston Soundpainting Ensemble, led by Dr. Minors at Kington University, is representated by a section a varied set of performers, using woodwind, brass, voice and percussion, spanning popular, classical and world styles. This performance consists of: Philip Warda (electronic instruments,...

  2. 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

  3. Une seule manière d'utiliser les exceptions ? Une étude empirique de 21 applications Java

    OpenAIRE

    G. De Montauzan, Maxence; Monperrus, Martin

    2012-01-01

    Le langage Java offre un puissant système de gestion des exceptions et de traitement des erreurs. L'étude de différentes applications Java peut permettre de distinguer différentes utilisations de ce système. Ce papier étudie les utilisations des exceptions pour constater les différences ou similitudes entre 21 applications. Les résultats permettent de constater de fortes différences entre les applications et dans l'ensemble une gestion très variée des exceptions.

  4. Goa, une autre Inde

    OpenAIRE

    Martine Amiot-Guigaz

    2007-01-01

    Carte de l’Inde Goa. Le nom évoque les plages mythiques et les hippies qui, dans les années 70, en avaient fait leur Eden. Aujourd’hui la déferlante touristique, tant occidentale qu’indienne – les stars de Bollywood s’y retrouvent –, a envahi ce lieu paradisiaque tout comme les amateurs de raves techno. Sur plus d’une centaine de kilomètres du nord au sud se déroulent d’immenses plages au sable fin, bordées de cocotiers. Délimité à l'ouest par l’océan Indien et à l'est par la chaîne montag....

  5. Goa, une autre Inde

    Directory of Open Access Journals (Sweden)

    Martine Amiot-Guigaz

    2007-01-01

    Full Text Available Carte de l’Inde Goa. Le nom évoque les plages mythiques et les hippies qui, dans les années 70, en avaient fait leur Eden. Aujourd’hui la déferlante touristique, tant occidentale qu’indienne – les stars de Bollywood s’y retrouvent –, a envahi ce lieu paradisiaque tout comme les amateurs de raves techno. Sur plus d’une centaine de kilomètres du nord au sud se déroulent d’immenses plages au sable fin, bordées de cocotiers. Délimité à l'ouest par l’océan Indien et à l'est par la chaîne montag...

  6. 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.

  7. Multinomial logistic regression ensembles.

    Science.gov (United States)

    Lee, Kyewon; Ahn, Hongshik; Moon, Hojin; Kodell, Ralph L; Chen, James J

    2013-05-01

    This article proposes a method for multiclass classification problems using ensembles of multinomial logistic regression models. A multinomial logit model is used as a base classifier in ensembles from random partitions of predictors. The multinomial logit model can be applied to each mutually exclusive subset of the feature space without variable selection. By combining multiple models the proposed method can handle a huge database without a constraint needed for analyzing high-dimensional data, and the random partition can improve the prediction accuracy by reducing the correlation among base classifiers. The proposed method is implemented using R, and the performance including overall prediction accuracy, sensitivity, and specificity for each category is evaluated on two real data sets and simulation data sets. To investigate the quality of prediction in terms of sensitivity and specificity, the area under the receiver operating characteristic (ROC) curve (AUC) is also examined. The performance of the proposed model is compared to a single multinomial logit model and it shows a substantial improvement in overall prediction accuracy. The proposed method is also compared with other classification methods such as the random forest, support vector machines, and random multinomial logit model. PMID:23611203

  8. 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

  9. 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.

  10. 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...

  11. Ensemble of Causal Trees

    International Nuclear Information System (INIS)

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite. (author)

  12. Ensemble of Causal Trees

    Science.gov (United States)

    Bialas, Piotr

    2003-10-01

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite.

  13. 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...

  14. 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].

  15. 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.

  16. 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...

  17. 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

  18. 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...

  19. A CLUE for CLUster Ensembles

    OpenAIRE

    Kurt Hornik

    2005-01-01

    Cluster ensembles are collections of individual solutions to a given clustering problem which are useful or necessary to consider in a wide range of applications. The R package clue provides an extensible computational environment for creating and analyzing cluster ensembles, with basic data structures for representing partitions and hierarchies, and facilities for computing on these, including methods for measuring proximity and obtaining consensus and "secondary" clusterings....

  20. 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...... 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...

  1. 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 ...

  2. Quantum Gibbs ensemble Monte Carlo

    International Nuclear Information System (INIS)

    We present a path integral Monte Carlo method which is the full quantum analogue of the Gibbs ensemble Monte Carlo method of Panagiotopoulos to study the gas-liquid coexistence line of a classical fluid. Unlike previous extensions of Gibbs ensemble Monte Carlo to include quantum effects, our scheme is viable even for systems with strong quantum delocalization in the degenerate regime of temperature. This is demonstrated by an illustrative application to the gas-superfluid transition of 4He in two dimensions

  3. 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.

  4. An automated Certification Authority

    CERN Document Server

    Shamardin, L V

    2002-01-01

    This note describe an approach to building an automated Certification Authority. It is compatible with basic requirements of RFC2527. It also supports Registration Authorities and Globus Toolkit grid-cert-renew automatic certificate renewal.

  5. Localization of atomic ensembles via superfluorescence

    OpenAIRE

    Macovei, M.; Evers, J.; Keitel, C. H.; Zubairy, M. S.

    2006-01-01

    The sub-wavelength localization of an ensemble of atoms concentrated to a small volume in space is investigated. The localization relies on the interaction of the ensemble with a standing wave laser field. The light scattered in the interaction of standing wave field and atom ensemble depends on the position of the ensemble relative to the standing wave nodes. This relation can be described by a fluorescence intensity profile, which depends on the standing wave field parameters, the ensemble ...

  6. Barrier Certificates Revisited

    OpenAIRE

    Dai, Liyun; Gan, Ting; Xia, Bican; Zhan, Naijun

    2013-01-01

    A barrier certificate can separate the state space of a con- sidered hybrid system (HS) into safe and unsafe parts ac- cording to the safety property to be verified. Therefore this notion has been widely used in the verification of HSs. A stronger condition on barrier certificates means that less expressive barrier certificates can be synthesized. On the other hand, synthesizing more expressive barrier certificates often means high complexity. In [9], Kong et al consid- ered how to relax the ...

  7. Jeux de rôles pour enfants : une nouvelle forme de fiction ludique

    Directory of Open Access Journals (Sweden)

    Sébastien Kapp

    2011-12-01

    Full Text Available Comment ethnographier la place de la création fictionnelle chez l’enfant ? Nous proposons ici une étude de cas d’une pratique à la croisée du jeu de rôle enfantin spontané et du jeu de rôle grandeur nature pour adulte. Menée sous la forme d’un stage estival, cette activité nous permet de comprendre comment adultes et enfants peuvent ponctuellement participer ensemble à l’écriture d’un récit qui prendra la forme d’un jeu en actes et en paroles. Une des caractéristiques principales de cette forme hybride est que l’enfant est placé dans une position d’auteur, d’acteur et de spectateur. Mais contrairement à ses propres jeux, il est en permanence sous la surveillance et la conduite d’adultes qui supervisent le développement du récit et la conformité des actions par rapport aux règles. Le jeune joueur est donc dans une posture originale : il produit une partie du contenu narratif du jeu dont il n’est pas l’acteur unique (en créant par exemple son personnage. Lui aussi veut raconter une histoire, mettre en place un scénario, créer des règles et faire jouer les adultes, comme dans son jeu enfantin. Mais les règles changent, il n’est plus omnipotent et doit jouer dans des cadres de simulation qu’il contribue à définir.

  8. 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...

  9. 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.

  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. 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...

  12. 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.

  13. A mollified Ensemble Kalman filter

    CERN Document Server

    Bergemann, Kay

    2010-01-01

    It is well recognized that discontinuous analysis increments of sequential data assimilation systems, such as ensemble Kalman filters, might lead to spurious high frequency adjustment processes in the model dynamics. Various methods have been devised to continuously spread out the analysis increments over a fixed time interval centered about analysis time. Among these techniques are nudging and incremental analysis updates (IAU). Here we propose another alternative, which may be viewed as a hybrid of nudging and IAU and which arises naturally from a recently proposed continuous formulation of the ensemble Kalman analysis step. A new slow-fast extension of the popular Lorenz-96 model is introduced to demonstrate the properties of the proposed mollified ensemble Kalman filter.

  14. 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...

  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. Pattern classification using ensemble methods

    CERN Document Server

    Rokach, Lior

    2009-01-01

    Researchers from various disciplines such as pattern recognition, statistics, and machine learning have explored the use of ensemble methodology since the late seventies. Thus, they are faced with a wide variety of methods, given the growing interest in the field. This book aims to impose a degree of order upon this diversity by presenting a coherent and unified repository of ensemble methods, theories, trends, challenges and applications. The book describes in detail the classical methods, as well as the extensions and novel approaches developed recently. Along with algorithmic descriptions o

  17. The Ensembl Variant Effect Predictor.

    Science.gov (United States)

    McLaren, William; Gil, Laurent; Hunt, Sarah E; Riat, Harpreet Singh; Ritchie, Graham R S; Thormann, Anja; Flicek, Paul; Cunningham, Fiona

    2016-01-01

    The Ensembl Variant Effect Predictor is a powerful toolset for the analysis, annotation, and prioritization of genomic variants in coding and non-coding regions. It provides access to an extensive collection of genomic annotation, with a variety of interfaces to suit different requirements, and simple options for configuring and extending analysis. It is open source, free to use, and supports full reproducibility of results. The Ensembl Variant Effect Predictor can simplify and accelerate variant interpretation in a wide range of study designs. PMID:27268795

  18. Ensemble and constrained clustering with applications

    OpenAIRE

    Abdala, D.D. (Daniel)

    2011-01-01

    Diese Arbeit stellt neue Entwicklungen in Ensemble und Constrained Clustering vor und enthält die folgenden wesentlichen Beiträge: 1) Eine Vereinigung von Constrained und Ensemble Clustering in einem einheitlichen Framework. 2) Eine neue Methode zur Messung und Visualisierung der Variabilität von Ensembles. 3) Ein neues, Random Walker basiertes Verfahren für Ensemble Clustering. 4) Anwendung von Ensemble Clustering für Bildsegmentierung. 5) Eine neue Consensus-Funktion für das Ensemble Cluste...

  19. 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.

  20. Multimodel ensembles of wheat growth

    DEFF Research Database (Denmark)

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

    2015-01-01

    such studies are difficult to organize and have only recently begun. We report on the largest ensemble study to date, of 27 wheat models tested in four contrasting locations for their accuracy in simulating multiple crop growth and yield variables. The relative error averaged over models was 24–38% for...

  1. 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

  2. Spectral Diagonal Ensemble Kalman Filters

    Czech Academy of Sciences Publication Activity Database

    Kasanický, Ivan; Mandel, Jan; Vejmelka, Martin

    2015-01-01

    Roč. 22, č. 4 (2015), s. 485-497. ISSN 1023-5809 R&D Projects: GA ČR GA13-34856S Grant ostatní: NSF(US) DMS -1216481 Institutional support: RVO:67985807 Keywords : data assimilation * ensemble Kalman filter * spectral representation Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.987, year: 2014

  3. Spectral Diagonal Ensemble Kalman Filters

    Czech Academy of Sciences Publication Activity Database

    Kasanický, Ivan; Mandel, Jan; Vejmelka, Martin

    2015-01-01

    Roč. 22, č. 4 (2015), s. 485-497. ISSN 1023-5809 R&D Projects: GA ČR GA13-34856S Grant ostatní: NSF(US) DMS-1216481 Institutional support: RVO:67985807 Keywords : data assimilation * ensemble Kalman filter * spectral representation Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.987, year: 2014

  4. Une ontologie pour la conception d'une plateforme collaborative exploitant une table multi- tactile et multi-modale

    OpenAIRE

    Joiron, Céline; Fürst, Frédéric; Kassel, Gilles; Jones, Alistair; Barthès, Jean-Paul,; Moulin, Claude; Lenne, Dominique

    2013-01-01

    L'objectif du projet TATIN-PIC (TAble Tactile Interactive et Plateforme Intelligente de Conception), est de développer une plateforme exploitant une table interactive multi-tactile et multi-modale dédiée à la conception préliminaire. À cette fin, une ontologie – OntoTATIN-PIC – est construite pour représenter les connaissances liées aux dispositifs et à l'activité de conception. Dans cet article, nous présentons, d'une part, l'originalité de cette ontologie : OntoTATIN-PIC étend l'ontologie f...

  5. 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...

  6. Energy saving certificates

    International Nuclear Information System (INIS)

    The French ministry of economy, finances and industry and the French agency of environment and energy mastery (Ademe) have organized on November 8, 2005, a colloquium for the presentation of the energy saving certificates, a new tool to oblige the energy suppliers to encourage their clients to make energy savings. This document gathers the transparencies presented at this colloquium about the following topics: state-of-the-art and presentation of the energy saving certificates system: presentation of the EEC system, presentation of the EEC standard operations; the energy saving certificates in Europe today: energy efficiency commitment in UK, Italian white certificate scheme, perspectives of the different European systems. (J.S.)

  7. 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 ...

  8. Chapitre 4. Pour une définition du « numérique »

    OpenAIRE

    Vitali-Rosati, Marcello

    2014-01-01

    On ne peut pas parler d’édition numérique sans approfondir le sens du mot « numérique » lui-même. L’édition numérique fait partie d’une série complexe de pratiques qui jalonnent désormais notre quotidien. Une réflexion théorique à propos de ce mot est indispensable pour pouvoir comprendre les caractéristiques structurales des nouvelles pratiques éditoriales et leur rapport avec la dimension de plus en plus numérique de l’ensemble de notre culture. Ce chapitre a l’ambition de clarifier la sign...

  9. Pour une approche pluridisciplinaire et transversale de la pensée benthamienne

    Directory of Open Access Journals (Sweden)

    Malik Bozzo-Rey

    2007-11-01

    Full Text Available Il continue d’exister un certain nombre d’idées reçues concernant la personnalité de Jeremy Bentham et sa méthode de travail. Ces idées peuvent avoir une connotation positive ou négative. Par exemple, Bentham est souvent considéré comme l’un des derniers héritiers d’une conception du savoir encyclopédique du siècle des Lumières. Mais son travail peut également être décrit au mieux comme l’amoncellement d’un ensemble d’écrits abordant des sujets extrêmement différents et au pire comme un amas ...

  10. 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'...

  11. 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...

  12. 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.

  13. Spectral diagonal ensemble Kalman filters

    Directory of Open Access Journals (Sweden)

    I. Kasanický

    2015-01-01

    Full Text Available 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.

  14. 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.

  15. Triticeae resources in Ensembl Plants.

    Science.gov (United States)

    Bolser, Dan M; Kerhornou, Arnaud; Walts, Brandon; Kersey, Paul

    2015-01-01

    Recent developments in DNA sequencing have enabled the large and complex genomes of many crop species to be determined for the first time, even those previously intractable due to their polyploid nature. Indeed, over the course of the last 2 years, the genome sequences of several commercially important cereals, notably barley and bread wheat, have become available, as well as those of related wild species. While still incomplete, comparison with other, more completely assembled species suggests that coverage of genic regions is likely to be high. Ensembl Plants (http://plants.ensembl.org) is an integrative resource organizing, analyzing and visualizing genome-scale information for important crop and model plants. Available data include reference genome sequence, variant loci, gene models and functional annotation. For variant loci, individual and population genotypes, linkage information and, where available, phenotypic information are shown. Comparative analyses are performed on DNA and protein sequence alignments. The resulting genome alignments and gene trees, representing the implied evolutionary history of the gene family, are made available for visualization and analysis. Driven by the case of bread wheat, specific extensions to the analysis pipelines and web interface have recently been developed to support polyploid genomes. Data in Ensembl Plants is accessible through a genome browser incorporating various specialist interfaces for different data types, and through a variety of additional methods for programmatic access and data mining. These interfaces are consistent with those offered through the Ensembl interface for the genomes of non-plant species, including those of plant pathogens, pests and pollinators, facilitating the study of the plant in its environment. PMID:25432969

  16. State Ensembles and Quantum Entropy

    Science.gov (United States)

    Kak, Subhash

    2016-06-01

    This paper considers quantum communication involving an ensemble of states. Apart from the von Neumann entropy, it considers other measures one of which may be useful in obtaining information about an unknown pure state and another that may be useful in quantum games. It is shown that under certain conditions in a two-party quantum game, the receiver of the states can increase the entropy by adding another pure state.

  17. 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...

  18. 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

  19. Web de données agricole : transformation de sources pour une ontologie modulaire

    OpenAIRE

    Amarger, F.; Roussey, C.; Chanet, J.P.; Haemmerlé, O.; Hernandez, N

    2013-01-01

    Nous souhaitons développer une ontologie pour annoter des corpus de documents sur la surveillance des cultures, la prévention des risques, la protection des cultures et les bonnes pratiques agricoles. Notre ontologie permettra aussi de stocker des données spatio-temporelles relatives aux observations faites sur le développement des cultures et les attaques des bio-agresseurs sur ces mêmes cultures. Le but étant de publier l’ensemble de ces données sur le web de données. Nous allons présenter ...

  20. 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...

  1. 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.…

  2. 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.

  3. 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...

  4. 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)

  5. 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.

  6. TIC et développement de compétences : une réalité conditionnée

    Directory of Open Access Journals (Sweden)

    Philippe Amblard

    2011-03-01

    Full Text Available La présente contribution met en lumière l’ensemble des conditions devant être prises en compte afin de créer un espace d’apprentissage en ligne favorisant l’acquisition de compétences TIC par les TIC chez l’apprenant. S’appuyant sur une expérience réussie de création et coordination pédagogique d’un dispositif de formation en ligne dédié à la préparation du C2i niveau 1, les auteurs explicitent le sens qu’ils ont souhaité donner à leurs ressources et parcours pédagogiques afin d’encourager le développement de compétences en ligne. Ils analysent également la mutation professionnelle qu’opère la FOAD dans la pratique pédagogique de l’enseignant et à plus large titre, dans l’ensemble de l’équipe pédagogique, soucieuse de voir progresser l’étudiant. Enfin, ils insistent sur la prégnance du contexte politico-économique qui malgré la bonne volonté pédagogique, conditionne largement la réussite des apprenants, usagers des dispositifs de FOAD.The present paper highlights all the conditions to be taken into account in order to create a space for promoting e-learning system supporting the acquisition of ICT (Information and Communication Technologies skills through ICT by the learner. Based on a successful experience of creating and teaching coordination of an e-learning mechanism dedicated to the preparation of C2i (Computer and Internet Certificate level 1, the authors clarify the sense they wanted to give their resources and learning paths to encourage online development of competences. They also analyze the job transfer operated by the DL (Distance Learning in educational practice of teacher and, on a broader basis, in the whole teaching staff, keen on seeing their student’s progress. Finally, they emphasize the significance of the political-economic context that, despite the goodwill teaching, widely determines the success of learners, users of devices ODL (Open and Distance Learning.

  7. Vers une photographie des sentiments

    Directory of Open Access Journals (Sweden)

    Elena Vaou

    2009-09-01

    Full Text Available Quand elle photographie le monde, Lee Miller ne se soucie pas autant de son imitation que de sa mise en spectacle. C’est justement cette mise en scène permanente de son objet d’exposition — que cela soit la vue du désert égyptien à travers sa fenêtre, l’explosion d’une bombe nazie, ou sa propre image comme sujet de désir —, qui met en évidence les traits dominant sa vie aussi bien que son œuvre. Fascinée par l’objectif dès son plus jeune âge, alors que photographiée nue par son père, elle dev...

  8. 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....

  9. 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.

  10. 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

  11. 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

  12. 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.

  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. A Selective Fuzzy Clustering Ensemble Algorithm

    OpenAIRE

    Kai Li; Peng Li

    2013-01-01

    To improve the performance of clustering ensemble method, a selective fuzzy clustering ensemble algorithm is proposed. It mainly includes selection of clustering ensemble members and combination of clustering results. In the process of member selection, measure method is defined to select the better clustering members. Then some selected clustering members are viewed as hyper-graph in order to select the more influential hyper-edges (or features) and to weight the selected features. For proce...

  16. Controllability of ensembles of linear dynamical systems

    OpenAIRE

    Schönlein, Michael; Helmke, Uwe

    2015-01-01

    We investigate the task of controlling ensembles of initial and terminal state vectors of parameter-dependent linear systems by applying parameter-independent open loop controls. Necessary, as well as sufficient, conditions for ensemble controllability are established, using tools from complex approximation theory. For real analytic families of linear systems it is shown that ensemble controllability holds only for systems with at most two independent parameters. We apply the results to netwo...

  17. 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, ...

  18. 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...

  19. Vers une ontologie formelle des artefacts

    OpenAIRE

    Kassel, Gilles

    2009-01-01

    Dans cet article, nous jetons les bases d'une ontologie formelle permettant de rendre compte de la nature générale des artefacts. L'objectif visé par une telle ontologie est d'aider à structurer des ontologies d'application dans des domaines où des artefacts spécifiques sont présents, autrement dit pratiquement tout domaine d'activité ! La conceptualisation s'appuie sur une littérature philosophique récente consacrée aux artefacts, que nous exploitons pour éclairer les choix de modélisation. ...

  20. Multi-Model Ensemble Wake Vortex Prediction

    Science.gov (United States)

    Koerner, Stephan; Holzaepfel, Frank; Ahmad, Nash'at N.

    2015-01-01

    Several multi-model ensemble methods are investigated for predicting wake vortex transport and decay. This study is a joint effort between National Aeronautics and Space Administration and Deutsches Zentrum fuer Luft- und Raumfahrt to develop a multi-model ensemble capability using their wake models. An overview of different multi-model ensemble methods and their feasibility for wake applications is presented. The methods include Reliability Ensemble Averaging, Bayesian Model Averaging, and Monte Carlo Simulations. The methodologies are evaluated using data from wake vortex field experiments.

  1. La certification ACQPA des peintures et systèmes de peinture : Un label de durabilité pour les maîtres d'ouvrages

    OpenAIRE

    BRIQUET, Philippe; HAMPARIAN, Serge

    2010-01-01

    L'ACQPA (Association pour la Certification et la Qualification en Peinture Anticorrosion) est une association tierce-partie qui délivre une marque volontaire de certification française pour la protection des ouvrages. Elle gère la qualité des produits, la qualification des opérateurs chargés de l'application et des inspecteurs chargés du contrôle. L'ACQPA certifie la protection anticorrosion des structures métalliques, des applications militaires navales (et terrestres en cours), des peinture...

  2. 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

  3. 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...

  4. 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...

  5. 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

  6. Certification of Pork Products

    OpenAIRE

    Nilsson, Tomas K.H.; Foster, Kenneth A.

    2005-01-01

    The objective of this paper is to provide insights on the welfare distributional impact on consumer and producer welfare resulting from the development and implementation of a credence certification program in the U.S. pork sector. The certification program can provide various levels of tracking and tracing in the marketing chain. The modeling framework follows that of Nilsson (2005), which encompasses product differentiation and substitution across meat products at the consumer level and acr...

  7. 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…

  8. 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.

  9. Les forêts tropicales en marge de la certification forestière

    OpenAIRE

    Tsayem Demaze, Moise

    2008-01-01

    La certification forestière a émergé au début des années 1990. Près de 20 ans après, cette activité, entre normalisation de la gestion forestière durable et marketing écologique, affiche une expansion continue en termes de surfaces forestières certifiées par deux des principaux organismes qui dominent le secteur : le Programme for Endorsement of Forest Certification schemes (PEFC) et le Forest Stewardship Council (FSC). Le traitement graphique et cartographique des données statistiques de ces...

  10. 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

  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. A Selective Fuzzy Clustering Ensemble Algorithm

    Directory of Open Access Journals (Sweden)

    Kai Li

    2013-12-01

    Full Text Available To improve the performance of clustering ensemble method, a selective fuzzy clustering ensemble algorithm is proposed. It mainly includes selection of clustering ensemble members and combination of clustering results. In the process of member selection, measure method is defined to select the better clustering members. Then some selected clustering members are viewed as hyper-graph in order to select the more influential hyper-edges (or features and to weight the selected features. For processing hyper-edges with fuzzy membership, CSPA and MCLA consensus function are generalized. In the experiments, some UCI data sets are chosen to test the presented algorithm’s performance. From the experimental results, it can be seen that the proposed ensemble method can get better clustering ensemble result.

  13. 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.

  14. 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 (...

  15. 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

  16. 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.)

  17. 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.

  18. 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...

  19. MASK : une méthode d'ingénierie des connaissances pour l'analyse et la structuration des connaissances

    OpenAIRE

    Aries, Serge; Le Blanc, Benoît; Ermine, Jean-Louis

    2008-01-01

    L'ensemble des connaissances d'une organisation est une véritable richesse qu'il convient de gérer au mieux. Il est souvent intéressant de rendre cette richesse tangible en terme d'informations, c'est à dire de rendre visible le capital de connaissances. Une visibilité accrue sur le patrimoine de connaissances a de multiples avantages. Ceci paraît évident si l'on se réfère aux objectifs énoncés ci-dessus : capitalisation (au sens non économique, proche de " mémorisation "), partage (on transm...

  20. 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...

  1. 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.

  2. 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.

  3. 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 ...

  4. 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…

  5. Derivation of Mayer Series from Canonical Ensemble

    Science.gov (United States)

    Xian-Zhi, Wang

    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.

  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. Atomic clock ensemble in space

    International Nuclear Information System (INIS)

    Atomic Clock Ensemble in Space (ACES) is a mission using high-performance clocks and links to test fundamental laws of physics in space. Operated in the microgravity environment of the International Space Station, the ACES clocks, PHARAO and SHM, will generate a frequency reference reaching instability and inaccuracy at the 1 · 10−16 level. A link in the microwave domain (MWL) and an optical link (ELT) will make the ACES clock signal available to ground laboratories equipped with atomic clocks. Space-to-ground and ground-to-ground comparisons of atomic frequency standards will be used to test Einstein's theory of general relativity including a precision measurement of the gravitational red-shift, a search for time variations of fundamental constants, and Lorentz Invariance tests. Applications in geodesy, optical time transfer, and ranging will also be supported. ACES has now reached an advanced technology maturity, with engineering models completed and successfully tested and flight hardware under development. This paper presents the ACES mission concept and the status of its main instruments.

  8. 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

  9. Study of a polarized proton source for a cyclotron using a high frequency transition (1961); Etude d'une source de protons polarises utilisant une transition haute frequence pour un cyclotron (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Thirion, J.; Beurtey, R.; Papineau, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The authors have developed an experimental unit yielding a jet of hydrogen or deuterium atoms in which the protons and deutons are polarized. By use of the 'adiabatic passage' method a proton polarisation approaching 100 per cent is assured. (authors) [French] Les auteurs ont mis au point un ensemble experimental permettant d'obtenir un jet d'atomes d'hydrogene ou de deuterium, dans lequel les protons et les deutons sont polarises. Grace a la methode du 'passage adiabatique' une polarisation de protons voisine de 100 pour cent est obtenue. (auteurs)

  10. 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 ...

  11. Le langage : une empreinte cognitive

    OpenAIRE

    Bourguignon, Nicolas

    2008-01-01

    Le présent article vise à proposer une synthèse critique du débat « nature vs nurture » sur la question du langage, de son acquisition et de sa place au sein de la nature et de la biologie humaine. L’accent y est mis sur une étude « mentaliste » du langage telle que proposée par l’école générativiste, sans pour autant en exclure le rôle du milieu social et contextuel dans le développement linguistique des individus. L’étude de ce dernier se justifie d’une part au travers des nombreuses découv...

  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

    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 (d-ECC). The ensemble based empirical copulas, ECC and d-ECC, are applied to wind forecasts from the high resolution ensemble system COSMO-DEEPS run operationally at the German...

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Ensemble Machine Learning Methods and Applications

    CERN Document Server

    Ma, Yunqian

    2012-01-01

    It is common wisdom that gathering a variety of views and inputs improves the process of decision making, and, indeed, underpins a democratic society. Dubbed “ensemble learning” by researchers in computational intelligence and machine learning, it is known to improve a decision system’s robustness and accuracy. Now, fresh developments are allowing researchers to unleash the power of ensemble learning in an increasing range of real-world applications. Ensemble learning algorithms such as “boosting” and “random forest” facilitate solutions to key computational issues such as face detection and are now being applied in areas as diverse as object trackingand bioinformatics.   Responding to a shortage of literature dedicated to the topic, this volume offers comprehensive coverage of state-of-the-art ensemble learning techniques, including various contributions from researchers in leading industrial research labs. At once a solid theoretical study and a practical guide, the volume is a windfall for r...

  19. 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...

  20. 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.

  1. Orbital magnetism in ensembles of ballistic billiards

    International Nuclear Information System (INIS)

    The magnetic response of ensembles of small two-dimensional structures at finite temperatures is calculated. Using semiclassical methods and numerical calculation it is demonstrated that only short classical trajectories are relevant. The magnetic susceptibility is enhanced in regular systems, where these trajectories appear in families. For ensembles of squares large paramagnetic susceptibility is obtained, in good agreement with recent measurements in the ballistic regime. (authors). 20 refs., 2 figs

  2. Coherent ensemble averaging techniques for impedance cardiography

    OpenAIRE

    Hurwitz, Barry E.; Shyu, Liang-Yu; Reddy, Sridhar P; Schneiderman, Neil; Nagel, Joachim H.

    1990-01-01

    EKG synchronized ensemble averaging of the impedance cardiogram tends to blur or suppress signal events due to signal jitter or event latency variability. Although ensemble averaging provides some improvement in the stability of the signal and signal to noise ratio under conditions of nonperiodic influences of respiration and motion, coherent averaging techniques were developed to determine whether further enhancement of the impedance cardiogram could be obtained. Physiological signals were o...

  3. 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...

  4. 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

  5. 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...

  6. Une rare cause de sciatique non discale: une polyarthrite rhumatoïde

    OpenAIRE

    Akasbi, Nessrine; Abourazzak, Fatima Ezzahra; Harzy, Taoufik

    2014-01-01

    La polyarthrite rhumatoïde est le rhumatisme inflammatoire chronique le plus fréquent. Ses complications neurologiques sont dominées par les neuropathies périphériques, cliniquement asymptomatiques, mais peuvent être détectées sur l’électromyogramme (EMG). Nous rapportons l'observation d'une patiente qui a présenté une neuropathie sensitivo-motrice aux deux membres inférieurs associée à une sciatique de topographie L5 d'origine rhumatoïde.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 9 CFR 151.4 - Pedigree certificate.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Pedigree certificate. 151.4 Section... Purebred Animals § 151.4 Pedigree certificate. A pedigree certificate for an animal of a breed listed in... English in the pedigree certificate for the animal or in a separate certificate appended to the...

  19. 46 CFR 107.258 - Crane certification.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Crane certification. 107.258 Section 107.258 Shipping... CERTIFICATION Inspection and Certification § 107.258 Crane certification. (a) The Coast Guard may accept current certificates issued by approved organizations as evidence of condition and suitability of cranes. The...

  20. 10 CFR 501.61 - Certification contents.

    Science.gov (United States)

    2010-01-01

    ... unit is expected to be placed in service. (9) Certification by an officer of the company or his... 10 Energy 4 2010-01-01 2010-01-01 false Certification contents. 501.61 Section 501.61 Energy... Certifications § 501.61 Certification contents. (a) A self-certification filed under section 201(d) of FUA...

  1. "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...

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. The Hydrologic Ensemble Prediction Experiment (HEPEX)

    Science.gov (United States)

    Wood, A. W.; Thielen, J.; Pappenberger, F.; Schaake, J. C.; Hartman, R. K.

    2012-12-01

    The Hydrologic Ensemble Prediction Experiment was established in March, 2004, at a workshop hosted by the European Center for Medium Range Weather Forecasting (ECMWF). With support from 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 in emergency management and water resources sectors. The strategy to meet this goal includes 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. HEPEX has organized about 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. Today, the HEPEX mission is to demonstrate the added value of hydrological ensemble prediction systems (HEPS) for emergency management and water resources sectors to make decisions that have important consequences for economy, public health, safety, and the environment. HEPEX is now organised around six major themes that represent 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. This poster presents an overview of recent and planned HEPEX activities, highlighting case studies that exemplify the focus and objectives of HEPEX.

  7. 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.

  8. 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 ...

  9. Transformation d’une Base de données relationnelle en Linked Data

    OpenAIRE

    HASNAOUI, Nabila; DJEZIRI, Salima

    2014-01-01

    Très nombreuses données disponibles actuellement sur le Web qui pourraient contribués au Web de donnée ce qui facilite leur accès, partage et alignement. Malheureusement, la majorité de ces données contenues dans les bases de données restent inaccessible par les applications Web. Le W3C a proposé des standards de représentation des données et leur schéma (RDF et RDFS). Dans le présent travail nous proposons un ensemble de règles de passage qui prend au départ des données d’une ...

  10. Construction d'une ontologie de descripteurs UCD en astronomie

    OpenAIRE

    Nauer, Emmanuel; Richard, Alexandre; Derriere, Sébastien; Genova, Françoise; Napoli, Amedeo; Toussaint, Yannick

    2005-01-01

    Les descripteurs UCD (Unified Content Descriptors) permettent de décrire des données d'astronomie. Une première étape de standardisation est restée purement syntaxique. Nous proposons d'y associer une sémantique formelle par la construction d'une ontologie. Dans cet article, nous présentons d'une part, une méthodologie pour construire une ontologie des UCD normalisés en OWL, et d'autre part une méthode d'annotation dans laquelle l'ontologie est exploitée pour l'attribution semi-automatique d'...

  11. 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.

  12. 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.

  13. Ensemble approach for differentiation of malignant melanoma

    Science.gov (United States)

    Rastgoo, Mojdeh; Morel, Olivier; Marzani, Franck; Garcia, Rafael

    2015-04-01

    Melanoma is the deadliest type of skin cancer, yet it is the most treatable kind depending on its early diagnosis. The early prognosis of melanoma is a challenging task for both clinicians and dermatologists. Due to the importance of early diagnosis and in order to assist the dermatologists, we propose an automated framework based on ensemble learning methods and dermoscopy images to differentiate melanoma from dysplastic and benign lesions. The evaluation of our framework on the recent and public dermoscopy benchmark (PH2 dataset) indicates the potential of proposed method. Our evaluation, using only global features, revealed that ensembles such as random forest perform better than single learner. Using random forest ensemble and combination of color and texture features, our framework achieved the highest sensitivity of 94% and specificity of 92%.

  14. 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).

  15. 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.)

  16. 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.

  17. 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.

  18. 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...

  19. 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)

  20. 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...

  1. Native ultrametricity of sparse random ensembles

    Science.gov (United States)

    Avetisov, V.; Krapivsky, P. L.; Nechaev, S.

    2016-01-01

    We investigate the eigenvalue density in ensembles of large sparse Bernoulli random matrices. Analyzing in detail the spectral density of ensembles of linear subgraphs, we discuss its ultrametric nature and show that near the spectrum boundary, the tails of the spectral density exhibit a Lifshitz singularity typical for Anderson localization. We pay attention to an intriguing connection of the spectral density to the Dedekind η-function. We conjecture that ultrametricity emerges in rare-event statistics and is inherit to generic complex sparse systems.

  2. Ensemble Enabled Weighted PageRank

    CERN Document Server

    Luo, Dongsheng; Hu, Renjun; Duan, Liang; Ma, Shuai

    2016-01-01

    This paper describes our solution for WSDM Cup 2016. Ranking the query independent importance of scholarly articles is a critical and challenging task, due to the heterogeneity and dynamism of entities involved. Our approach is called Ensemble enabled Weighted PageRank (EWPR). To do this, we first propose Time-Weighted PageRank that extends PageRank by introducing a time decaying factor. We then develop an ensemble method to assemble the authorities of the heterogeneous entities involved in scholarly articles. We finally propose to use external data sources to further improve the ranking accuracy. Our experimental study shows that our EWPR is a good choice for ranking scholarly articles.

  3. 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.

  4. 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...

  5. 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

  6. 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

  7. 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

  8. PULSE Pilot Certification Results

    Directory of Open Access Journals (Sweden)

    Pamela Pape-Lindstrom

    2015-08-01

    Full Text Available The pilot certification process is an ambitious, nationwide endeavor designed to motivate important changes in life sciences education that are in line with the recommendations of the 2011 Vision and Change Report: A Call to Action (American Association for the Advancement of Science [AAAS], 2011.  It is the goal of the certification process to acknowledge departments that have progressed towards full implementation of the tenets of Vision and Change and to motivate departments that have not begun to adopt the recommendations to consider doing so.  More than 70 life science departments applied to be part of the pilot certification process, funded by a National Science Foundation grant, and eight were selected based on initial evidence of transformed and innovative educational practices.  The programs chosen represent a wide variety of schools, including two-year colleges, liberal-arts institutions, regional comprehensive colleges, research universities and minority serving institutions.  Outcomes from this pilot were released June 1, 2015 (www.pulsecommunity.org, with all eight programs being recognized as having progressed along a continuum of change.  Five levels of achievement were defined as PULSE Pilot Progression Levels.  Of the eight departments in the pilot, one achieved “PULSE Progression Level III: Accomplished”.  Six departments achieved “PULSE Progression Level II: Developing” and one pilot department achieved “PULSE Progression Level I: Beginning”.  All of the schools have made significant movement towards the recommendations of Vision and Change relative to a traditional life sciences curriculum.  Overall, the response from the eight pilot schools has been positive. 

  9. 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...

  10. 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.

  11. 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 ...

  12. Paper Lives: Certification vs. Licensure

    Directory of Open Access Journals (Sweden)

    Gaye YILMAZ

    2015-03-01

    Full Text Available Since the mid-1990s certification has increasingly been considered as a tool to increase the chance to find job particularly by youngsters. However under the circumstances that exist today it is known that having certificates does not automatically lead to get job, even contrary job seekers may remain jobless after they pay huge amounts of money to certfication firms. The very fast increase in the number of certfying firms confirms the fact that there is an ongoing demand for short term qualification courses. Another process which accompanies to private certification is that the loosing ground in public education that despite corporations still care about diplomas in hiring they reject job applications in the case of absence of certificates. In this study certification as a popular phenomenon has been compared with licensure in the context of waged engineers and their chambers. As a consequence of the analyses made for this study, it may be concluded that there is a capital accumulation which is carried out via two layers of working classes: masses who are obliged to be certified and waged laborers who work in certification industry in order to improve skills of those who are in need to be certified. During reviewing of literature it has also been witnessed that the academic writings focusing on the numbers, wages and working conditions of trainers hired by certification firms is virtually non exist. Therefore study suggests further researches especially on waged trainers working in private certification firms.

  13. Faster, less expensive package certifications

    International Nuclear Information System (INIS)

    The U.S. Department of Energy Packaging Certification Staff (PCS) has been reviewing ways to shorten the radioactive material packaging certification process and reduce the overall costs of obtaining certification. The PCS can help to identify existing certified packaging designs that may meet a shipper's needs. If it is necessary to design a new packaging, then the fastest, easiest way toward certification is through the use of common designs and materials already familiar to the PCS (though this is not always possible or desirable). The shipper should be realistic about the amount of time, money, and documentation necessary to obtain a certification, and should involve the PCS early in the planning of the packaging. The PCS will not do design work or recommend a design, but can warn of potential pitfalls. The Safety Analysis Report for Packaging (SARP) is the basis for certification; therefore, the adequacy of the SARP should be the focal point of all efforts toward certification. Technical services provided by the PCS can help in the preparation of the SARP and can accelerate the certification process

  14. 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.

  15. Symplectic structure of the real Ginibre ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Sommers, Hans-Juergen [Fachbereich Physik, Universitaet Duisburg-Essen, 47048 Duisburg (Germany)

    2007-07-20

    We give a simple derivation of all n-point densities for the eigenvalues of the real Ginibre ensemble with even dimension N as quaternion determinants. A very simple symplectic kernel governs both the real and complex correlations. One- and two-point correlations are discussed in more detail. Scaling forms for large dimension N are derived. (fast track communication)

  16. 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)

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Embedded feature ranking for ensemble MLP classifiers

    OpenAIRE

    Windeatt, T; Duangsoithong, R; Smith, R

    2011-01-01

    A feature ranking scheme for multilayer perceptron (MLP) ensembles is proposed, along with a stopping criterion based upon the out-of-bootstrap estimate. To solve multi-class problems feature ranking is combined with modified error-correcting output coding. Experimental results on benchmark data demonstrate the versatility of the MLP base classifier in removing irrelevant features.

  2. Ensemble Filtering in Air Quality Models

    Czech Academy of Sciences Publication Activity Database

    Eben, Kryštof; Juruš, Pavel; Resler, Jaroslav; Belda, M.; Pelikán, Emil

    Brno : Masaryk University, 2007 - (Horová, I.; Hřebíček, J.) ISBN 978-80-210-4333-6. [ TIES 2007. Annual Meeting of the International Environmental Society /18./. 16.08.2007-20.08.2007, Mikulov] Institutional research plan: CEZ:AV0Z10300504 Keywords : air quality models * data assimilation * ensemble filtering

  3. 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

  4. 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.

  5. 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.)

  6. 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.

  7. L’accès aux ressources d’une formation guidé par des ontologies

    Directory of Open Access Journals (Sweden)

    Marie-Hélène Abel

    2006-01-01

    Full Text Available [Français] Beaucoup de ressources sont mises à contribution pour supporter une formation de type e-learning. L’un des objectifs du projet MEMORAe est de rendre ces ressources plus accessibles aux apprenants. Ce projet propose une approche fondée sur une mémoire organisationnelle de l’ensemble des notions et des ressources de la formation. Un principe est d’indexer ces ressources sur les concepts d’ontologie. Nous décrivons les moyens déployés à cette fin. Nous présentons les scénarios par lesquels les apprenants accèdent aux connaissances en parcourant ces ontologies. Enfin, nous illustrons notre propos à l’aide de deux applications actuellement mises en place en université. [English] Many resources are now available in order to support e-learning. One objective of the MEMORAe project is to make these resources more accessible to the students. This project proposes an approach based on an organizational memory of the notions and resources of the formation. A principle is to index these resources on the concepts of some ontologies. We describe the means implemented in this aim. We present the manner in which the students reach the knowledge, by moving in these ontologies. At last, we illustrate our presentation by means of two applications recently set up in some universities.

  8. Land Cover Mapping Using Ensemble Feature Selection Methods

    CERN Document Server

    Gidudu, A; Marwala, T

    2008-01-01

    Ensemble classification is an emerging approach to land cover mapping whereby the final classification output is a result of a consensus of classifiers. Intuitively, an ensemble system should consist of base classifiers which are diverse i.e. classifiers whose decision boundaries err differently. In this paper ensemble feature selection is used to impose diversity in ensembles. The features of the constituent base classifiers for each ensemble were created through an exhaustive search algorithm using different separability indices. For each ensemble, the classification accuracy was derived as well as a diversity measure purported to give a measure of the inensemble diversity. The correlation between ensemble classification accuracy and diversity measure was determined to establish the interplay between the two variables. From the findings of this paper, diversity measures as currently formulated do not provide an adequate means upon which to constitute ensembles for land cover mapping.

  9. 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...

  10. 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.

  11. 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...

  12. Personnel training and certification

    International Nuclear Information System (INIS)

    In order to make the full benefits of neutron radiography available in the nondestructive test (NDT) field, it has been necessary to formalize its application. A group under the Penetrating Radiation Committee of the American Society for Nondestructive Testing (ASNT) was organized to prepare a recommended practice for neutron radiography. The recommended practices require the establishment of an appropriate certification program. The requirements on the employer to establish and maintain a qualification and certification program are outlined. To conduct a program of nondestructive testing using neutron radiography requires the usual three levels of qualified and certified personnel. The program is administered by a Level III person. Routine exposure, reviews, and reporting of test results are the responsibilities of Level I and Level II personnal. The amount of training and nature of the required practical examination are also specified. The recommended practices document assures users that NDT work in the field of neutron radiography is performed by qualified personnel. Although no training courses are available to provide experience in the depth required by the recommended practices document, SNT-TC-1A, short courses are provided at a number of locations to familarize user's representatives with the interpretation of neutron radiographs and capabilities and limitations of the technique

  13. Une approche diachronique des TMS : usage de données quantitatives dans une grande entreprise

    OpenAIRE

    Mardon, Céline; Buchmann, Willy; Volkoff, Serge

    2013-01-01

    Cet article se base sur la partie quantitative d’une recherche en ergonomie dont le but est de comprendre comment des évolutions du travail ont favorisé ou limité la survenue et la persistance de troubles musculo-squelettiques (TMS) chez des opérateurs d’un groupe industriel aéronautique, avec une approche diachronique des faits étudiés. Un observatoire, fondé sur le recueil systématique de données quantitatives auprès des opérateurs (dispositif Evrest), permet de mettre en relation les facte...

  14. 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.

  15. 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...

  16. 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, an...

  17. 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.

  18. 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...

  19. Une introduction à l'univers de Briefs

    OpenAIRE

    Le Thanh, Nhan

    2013-01-01

    Nous proposons dans cet article d'étudier une structure d'information élémentaire, appelée Brief, permettant d'annoter des observations de phénomènes dans un contexte spatiotemporel via les réseaux d'interconnexion. Une des particularités de ces Briefs est qu'ils peuvent être utilisés dans une observation effectuée par l'homme ou par la machine à travers les objets communicants Cette forme d'annotation permettra une mise en place des services de traitement automatiques ou manuels des annotati...

  20. 12 CFR 561.9 - Certificate account.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Certificate account. 561.9 Section 561.9 Banks... AFFECTING ALL SAVINGS ASSOCIATIONS § 561.9 Certificate account. The term certificate account means a savings account evidenced by a certificate that must be held for a fixed or minimum term....

  1. Certification of district heating substations

    Energy Technology Data Exchange (ETDEWEB)

    2007-01-15

    These Technical Regulations, F:103-6, have been produced and published by the Swedish District Heating Association in conjunction with manufacturers. Approved testing is part of the process of obtaining certification for a district heating substation. In addition, the process includes a review of documentation and of the manufacturer's production inspection procedures. A certified unit fulfils the requirements set out in the Association's document F:101, General Technical Requirements. Until further notice, the Association has selected SP Technical Research Institute of Sweden for certification of district heating substations. Certification means that the quality and function/performance of a prefabricated district heating substation have been examined and approved. Certification test method F:103-6 includes both static and dynamic tests and inspections. Detailed information on the district heating substation and its properties is given in the certification test reports. The unique feature of this certification is that the test reports are in the public domain. This is possible because the Association has full right of insight into the certification process, and because testing is performed in accordance with test programmes and procedures decided by the Association. In this document (F: 103-6), the Association specifies what is to be reported when SP carries out inspections at the manufacturer's premises. This can include details of claims lodged with the manufacturer and/or non-compliances with the required specification of the district heating substation. Such cases will be considered by a Certification Panel. Test reports and certificates provide information on the district heating substation's properties and performance, which can be used when assessing the substations. The technical tests do not address the long-term properties of substations, but SP's inspection specifically includes visual examination and application of its

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. Vers une commune humanité ? Perspectives croisées sur l’émergence de la cybersanté mondiale

    OpenAIRE

    Duclos, Vincent

    2013-01-01

    Les dernières années ont vu émerger de nombreuses initiatives ayant recours aux télé-technologies pour prendre en charge la santé à une échelle mondiale. Cet article retrace la généalogie d’un ensemble de discours et pratiques rassemblées sous le concept de cybersanté mondiale. D’une part, celle-ci émerge dans le contexte de la montée des technologies de l’information et de la communication pour le développement, qui visent à réduire la fracture numérique et favoriser le développement humain ...

  7. Le slogan publicitaire, dynamique linguistique et vitalité sociale : la construction d'une esthétique sociale à travers la communication publicitaire

    OpenAIRE

    Lee, Chang-Hoon

    2014-01-01

    Éternel objet de polémique, la publicité française, comme miroir social, consolide aussi notre lien social. L’examen de son élément langagier, le slogan, peut apporter beaucoup à la sociologie. Dans la perspective d’une socialité langagière et sous la forme du jeu de langage, sa dynamique linguistique se révèle comme une nouvelle manifestation semi-consciente d’un désir de transgresser les règles et d’être ensemble. Son style et son climat reflètent finalement baroquisme et hédonisme comme ai...

  8. 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...

  9. Sampling Motif-Constrained Ensembles of Networks

    Science.gov (United States)

    Fischer, Rico; Leitão, Jorge C.; Peixoto, Tiago P.; Altmann, Eduardo G.

    2015-10-01

    The statistical significance of network properties is conditioned on null models which satisfy specified properties but that are otherwise random. Exponential random graph models are a principled theoretical framework to generate such constrained ensembles, but which often fail in practice, either due to model inconsistency or due to the impossibility to sample networks from them. These problems affect the important case of networks with prescribed clustering coefficient or number of small connected subgraphs (motifs). In this Letter we use the Wang-Landau method to obtain a multicanonical sampling that overcomes both these problems. We sample, in polynomial time, networks with arbitrary degree sequences from ensembles with imposed motifs counts. Applying this method to social networks, we investigate the relation between transitivity and homophily, and we quantify the correlation between different types of motifs, finding that single motifs can explain up to 60% of the variation of motif profiles.

  10. Sampling motif-constrained ensembles of networks

    CERN Document Server

    Fischer, Rico; Peixoto, Tiago P; Altmann, Eduardo G

    2015-01-01

    The statistical significance of network properties is conditioned on null models which satisfy spec- ified properties but that are otherwise random. Exponential random graph models are a principled theoretical framework to generate such constrained ensembles, but which often fail in practice, either due to model inconsistency, or due to the impossibility to sample networks from them. These problems affect the important case of networks with prescribed clustering coefficient or number of small connected subgraphs (motifs). In this paper we use the Wang-Landau method to obtain a multicanonical sampling that overcomes both these problems. We sample, in polynomial time, net- works with arbitrary degree sequences from ensembles with imposed motifs counts. Applying this method to social networks, we investigate the relation between transitivity and homophily, and we quantify the correlation between different types of motifs, finding that single motifs can explain up to 60% of the variation of motif profiles.

  11. 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...

  12. 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...

  13. 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 ...

  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. 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...

  16. The ensemble of random Markov matrices

    International Nuclear Information System (INIS)

    The ensemble of random Markov matrices is introduced as a set of Markov or stochastic matrices with the maximal Shannon entropy. The statistical properties of the stationary distribution π, the average entropy growth rate h and the second-largest eigenvalue ν across the ensemble are studied. It is shown and heuristically proven that the entropy growth rate and second-largest eigenvalue of Markov matrices scale on average with the dimension of the matrices d as h∼log(O(d)) and |ν|∼d−1/2, respectively, yielding the asymptotic relation hτc∼1/2 between the entropy h and the correlation decay time τ = −1/log|ν|. Additionally, the correlation between h and τc is analysed; it decreases with increasing dimension d

  17. DEECO: an ensemble-based component system

    Czech Academy of Sciences Publication Activity Database

    Bureš, Tomáš; Gerostathopoulos, I.; Hnětynka, P.; Keznikl, Jaroslav; Kit, M.; Plášil, F.

    New York: ACM, 2013, s. 81-90. ISBN 978-1-4503-2122-8. [CBSE 2013. International ACM SIGSOFT Symposium on Component-Based Software Engineering /16./. Vancouver (CA), 17.06.2013-21.06.2013] Grant ostatní: GA AV ČR(CZ) GAP202/11/0312; UK(CZ) SVV-2013-267312 Institutional support: RVO:67985807 Keywords : component model * emergent architecture * component ensembles * autonomic systems * development process * runtime framework Subject RIV: IN - Informatics, Computer Science

  18. Spectral Diagonal Covariance in Ensemble Kalman Filter

    Czech Academy of Sciences Publication Activity Database

    Kasanický, Ivan; Eben, Kryštof; Mandel, Jan; Vejmelka, Martin

    Munich: Ludwig Maximilians University, 2014. s. 10-10. [ISDA 2014. International Conference on Intelligent Systems Design and Applications. 24.02.2014-28.02.2014, Munich] R&D Projects: GA ČR GA13-34856S Grant ostatní: NSF DMS -1216481 Institutional support: RVO:67985807 Keywords : data assimilation * ensemble Kalman filter * diagonal covariance Subject RIV: DG - Athmosphere Sciences, Meteorology http://www.isda2014.physik.uni-muenchen.de/index.html

  19. 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 ...

  20. Statistical Ensemble Theory of Gompertz Growth Model

    OpenAIRE

    Takuya Yamano

    2009-01-01

    An ensemble formulation for the Gompertz growth function within the framework of statistical mechanics is presented, where the two growth parameters are assumed to be statistically distributed. The growth can be viewed as a self-referential process, which enables us to use the Bose-Einstein statistics picture. The analytical entropy expression pertain to the law can be obtained in terms of the growth velocity distribution as well as the Gompertz function itself for the whole process.

  1. Statistical Ensemble Theory of Gompertz Growth Model

    Directory of Open Access Journals (Sweden)

    Takuya Yamano

    2009-11-01

    Full Text Available An ensemble formulation for the Gompertz growth function within the framework of statistical mechanics is presented, where the two growth parameters are assumed to be statistically distributed. The growth can be viewed as a self-referential process, which enables us to use the Bose-Einstein statistics picture. The analytical entropy expression pertain to the law can be obtained in terms of the growth velocity distribution as well as the Gompertz function itself for the whole process.

  2. 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 ...

  3. Spectral Diagonal Covariance in Ensemble Kalman Filter

    Czech Academy of Sciences Publication Activity Database

    Kasanický, Ivan; Eben, Kryštof; Mandel, Jan; Vejmelka, Martin

    Munich : Ludwig Maximilians University, 2014. s. 10-10. [ISDA 2014. International Conference on Intelligent Systems Design and Applications. 24.02.2014-28.02.2014, Munich] R&D Projects: GA ČR GA13-34856S Grant ostatní: NSF DMS-1216481 Institutional support: RVO:67985807 Keywords : data assimilation * ensemble Kalman filter * diagonal covariance Subject RIV: DG - Athmosphere Sciences, Meteorology http://www.isda2014.physik.uni-muenchen.de/index.html

  4. Ensemble Models with Trees and Rules

    OpenAIRE

    Akdemir, Deniz

    2011-01-01

    In this article, we have proposed several approaches for post processing a large ensemble of prediction models or rules. The results from our simulations show that the post processing methods we have considered here are promising. We have used the techniques developed here for estimation of quantitative traits from markers, on the benchmark "Bostob Housing"data set and in some simulations. In most cases, the produced models had better prediction performance than, for example, the ones produce...

  5. 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.

  6. 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.

  7. Developments of a Targeted Ensemble Prediction System

    Science.gov (United States)

    Hersbach, H.; Mureau, R.; Opsteegh, J. D.; Barkmeijer, J.

    2003-04-01

    Based on results presented in a previous paper, an Ensemble Prediction System, especially designed for the short-range to early-medium range for the European domain (TEPS), was further developed. Between 1 January 1999 and 27 February 2000 this system was run for two cases per week. Results were compared to the ensemble prediction system (EPS) that was operational at the European Centre for Medium-Range Weather Forecasts at the time. The focus was on weather parameters. Several configurations were tested. Besides perturbations that optimize total error growth for the European domain at 48 h, perturbations relevant for shorter forecast times were included as well. Firstly, in accordance with EPS, evolved northern hemispheric singular vectors (ETEPS) and secondly, targeted singular vectors with an optimization time of 12 h (STEPS) were added. Compared to EPS, ensemble spread was increased in the short range, having a beneficial effect on statistical properties such as reliability and the frequency of outliers. Spread-skill correlations improved as well. Best performance was found for the STEPS configuration. The impact on Brier scores, relative operating characteristic curves and cost-loss analyses was less clear. From the singular vector point of view, the positive impact of using targeted perturbations is evident. However, after integration (STEPS or ETEPS), it was difficult to find synoptic cases in which this clear impact is still present.

  8. Microcanonical ensemble extensive thermodynamics of Tsallis statistics

    International Nuclear Information System (INIS)

    The microscopic foundation of the generalized equilibrium statistical mechanics based on the Tsallis entropy is given by using the Gibbs idea of statistical ensembles of the classical and quantum mechanics.The equilibrium distribution functions are derived by the thermodynamic method based upon the use of the fundamental equation of thermodynamics and the statistical definition of the functions of the state of the system. It is shown that if the entropic index ξ = 1/q - 1 in the microcanonical ensemble is an extensive variable of the state of the system, then in the thermodynamic limit z bar = 1/(q - 1)N = const the principle of additivity and the zero law of thermodynamics are satisfied. In particular, the Tsallis entropy of the system is extensive and the temperature is intensive. Thus, the Tsallis statistics completely satisfies all the postulates of the equilibrium thermodynamics. Moreover, evaluation of the thermodynamic identities in the microcanonical ensemble is provided by the Euler theorem. The principle of additivity and the Euler theorem are explicitly proved by using the illustration of the classical microcanonical ideal gas in the thermodynamic limit

  9. 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 $w_0$.

  10. Multivariate localization methods for ensemble Kalman filtering

    Science.gov (United States)

    Roh, S.; Jun, M.; Szunyogh, I.; Genton, M. G.

    2015-12-01

    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.

  11. 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

  12. Ensemble Clustering using Semidefinite Programming with Applications.

    Science.gov (United States)

    Singh, Vikas; Mukherjee, Lopamudra; Peng, Jiming; Xu, Jinhui

    2010-05-01

    In this paper, we study the ensemble clustering problem, where the input is in the form of multiple clustering solutions. The goal of ensemble clustering algorithms is to aggregate the solutions into one solution that maximizes the agreement in the input ensemble. We obtain several new results for this problem. Specifically, we show that the notion of agreement under such circumstances can be better captured using a 2D string encoding rather than a voting strategy, which is common among existing approaches. Our optimization proceeds by first constructing a non-linear objective function which is then transformed into a 0-1 Semidefinite program (SDP) using novel convexification techniques. This model can be subsequently relaxed to a polynomial time solvable SDP. In addition to the theoretical contributions, our experimental results on standard machine learning and synthetic datasets show that this approach leads to improvements not only in terms of the proposed agreement measure but also the existing agreement measures based on voting strategies. In addition, we identify several new application scenarios for this problem. These include combining multiple image segmentations and generating tissue maps from multiple-channel Diffusion Tensor brain images to identify the underlying structure of the brain. PMID:21927539

  13. 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.

  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. 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.

  16. Michel Houellebecq : un homme, une (soumission

    Directory of Open Access Journals (Sweden)

    Marc Smeets

    2015-12-01

    Full Text Available Michel Houellebecq, l’auteur le plus controversé de la littérature française contemporaine, semble s’astreindre à une seule et unique mission : celle d’être « vrai » à n’importe quel prix. Observateur et peintre de la société actuelle dans tous ses états, l’auteur de Soumission s’inscrit dans une tradition littéraire qui remonte au XIXe siècle, prolongeant ainsi les fictions de Balzac, de Zola et de Huysmans. De ses prédécesseurs Houellebecq hérite d’un certain goût pour la controverse, talent qui fait naturellement la pluie et le beau temps dans la presse. Le rôle que jouent la documentation et la figure du célibataire permet de situer l’écrivain dans le sillage de la tradition réalistico-naturaliste.

  17. 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.

  18. 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...

  19. 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...

  20. La reprise d'entreprise, une opportunité pour la mise en œuvre de la RSE en PME ?

    OpenAIRE

    Berger-Douce, Sandrine; Deschamps, Bérangère

    2010-01-01

    Depuis quelques années, à l'instar des grandes entreprises, les PME s'engagent chemin faisant dans des démarches de Responsabilité Sociale d'Entreprise (RSE) (Quairel et Auberger, 2005). Les obstacles à cette implication sont pourtant nombreux : au-delà de leurs ressources limitées (financières, humaines, en temps), elles doivent gérer l'ensemble des changements organisationnels induits par la RSE. La reprise d'entreprise, quant à elle, constitue une étape de rupture dans la vie des organisat...

  1. 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

  2. The legitimacy of biofuel certification

    OpenAIRE

    Partzsch, Lena

    2009-01-01

    Abstract The biofuel boom is placing enormous demands on existing cropping systems, with the most crucial consequences in the agri-food sector. The biofuel industry is responding by initiating private governance and certification. The Roundtable on Sustainable Palm Oil (RSPO) and the Cramer Commission, among others, have formulated criteria on ?sustainable? biofuel production and processing. This article explores the legitimacy of private governance and certification by the biofuel...

  3. 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.

  4. Vers une déontologie de l’enseignement

    OpenAIRE

    Prairat, Eirick

    2011-01-01

    Cet article propose une réflexion sur l’éthique professionnelle des enseignants. Plus précisément, il défend l’idée que l’orientation déontologique est devenue une perspective souhaitable. Celle-ci relève moins d’une aspiration morale que d’une attitude lucide qui a pris acte des changements intervenus dans la société et dans l’exercice du métier. Cet article s’attache aussi et surtout à définir à partir d’une triple caractérisation l’idée de minimalisme déontologique, montrant que c’est sans...

  5. 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.

  6. 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.

  7. La relation entre la certification environnementale ISO 14001 et la performance environnementale – Étude de cas sur quatre entreprises tunisiennes

    OpenAIRE

    Turki, Ahmed,

    2014-01-01

    L’objectif de cette recherche est d’évaluer l’impact de la certification à la norme ISO 14001 sur la performance environnementale. Une étude de cas, effectuée sur quatre entreprises, dont deux sont certifiées, montre l’existence d’un impact positif de la certification sur le plan environnemental. Toutefois, il est à noter que le niveau de pollution des entreprises enquêtées n’est pas conforme à la réglementation environnementale.

  8. The MIP ensemble simulation: local ensemble statistics in the Cosmic Web

    Science.gov (United States)

    Aragon-Calvo, M. A.

    2016-01-01

    We present a new technique that allows us to compute ensemble statistics on a local basis, directly relating halo properties to their local environment. This is achieved by the use of a correlated ensemble in which the large-scale structure (LSS) is common to all realizations while having each an independent halo population. The correlated ensemble can be stacked, effectively increasing the halo number density by an arbitrary factor, thus breaking the fundamental limit in the halo number density given by the halo mass function. This technique allows us to compute local ensemble statistics of the matter/halo distribution at any position in the simulation box, while removing the intrinsic stochasticity in the halo formation process and directly relating halo properties to their environment. We introduce the Multum In Parvo correlated ensemble simulation consisting of 220 realizations on a 32 h-1 Mpc box with 2563 particles each. This is equivalent in terms of effective volume and number of particles to a box of ˜193 h-1 Mpc of side with ˜15403 particles containing ˜5 × 106 haloes with a minimum mass of 3.25 × 109 h-1 M⊙. The potential of the technique presented here is illustrated by computing the local ensemble statistics of the halo ellipticity and halo shape-LSS alignment. We show that, while there are general trends in the ellipticity and alignment of haloes with their LSS, there are also significant spatial variations which has important implications for observational studies of galaxy shape and alignment.

  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. 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.

  11. 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.

  12. D'une sociologie de l'amateur à une pragmatique de l'attachement

    OpenAIRE

    Hennion, Antoine

    2005-01-01

    Du point de vue du sociologue, les amateurs n'ont rien d'une simple sous-population nouvelle à ajouter aux différents domaines d'intérêt de la sociologie de la culture. Selon moi, ce qu'ils appellent et permettent à la fois, c'est un véritable renversement de problématique, en redonnant une épaisseur, un contenu à l'amour de l'art. Il s'agit bien de remettre au centre de la sociologie de l'art ou du théâtre, l'enjeu même de ces pratiques - et vous savez le lourd passé sociologique de ce mot e...

  13. Opérationnalisation d'une ontologie: une méthode et un outil

    OpenAIRE

    Furst, Fréderic

    2004-01-01

    Le travail présenté dans cet article relève de l'ingénierie des ontologies de domaine au sein de systèmes à base de connaissances (SBC). la mise en œuvre d'une ontologie opérationnelle de la géométrie nous a permis de dégager des règles d'opérationnalisation d'une ontologie dans le modèle des graphes conceptuels. ces règles ont été implémentés dans le cadre d'un outil d'édition et d'opérationnalisation d'ontologies baptisé TooCoM.

  14. 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.

  15. Une fistule recto-vaginale rentrant dans le cadre d�un syndrome de Currarino

    Directory of Open Access Journals (Sweden)

    Mounia Lakhdar Idrissi

    2011-12-01

    Full Text Available Le syndrome de Currarino (SC est defini par une triade rassemblant une malformation ano-rectale, une agenesie sacree et une tumeur pre-sacree. Nous rapportons le cas d�une fille de 4 ans et demi ayant ete admise en consultation de gastro-enterologie pediatrique pour constipation avec issue de selle a travers un orifice vulvaire. La radiographie du rachis avait montre une agenesie sacree. Le fistulo-scanner a mis en evidence une fistule recto-vaginale et l�IRM pelvienne a confirme l�agenesie sacree et a retrouve une meningocele anterieure. La decouverte d�une malformation ano-rectale doit faire chercher une autre anomalie de la triade de Currarino. Cette affection, rare, necessite une prise en charge medico-chirurgicale assez complexe.

  16. 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.

  17. une approche comparative France-Bresil

    OpenAIRE

    Marques, Lívia Guerra

    2012-01-01

    La télévision a subi des mutations ces dernières années et traverse encore une période de changement. L’avènement de nouveaux formats et supports ainsi que la multiplication de l’offre de service en fait un média en constante évolution. Aujourd’hui, des réflexions sont en cours afin de comprendre la télévision «du présent et de l’avenir». Dans ce contexte, il est intéressant d’étudier comment les usagers en ressentent les changements. Parmi toutes les transformations technologi...

  18. 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 ...

  19. Reconstruction d’une lyre antique

    OpenAIRE

    Bélis, Annie

    2015-01-01

    Dans l’Antiquité grecque, l’instrument à cordes le plus populaire a toujours été la lyre : c’est avec elle que les enfants s’initiaient à la musique ; dès qu’ils savaient lire, ils se rendaient chez un « cithariste » qui n’était pas, contrairement à ce que l’on pourrait croire, un professeur de cithare, mais un professeur de lyre : d’innombrables coupes à figures rouges représentent des scènes d’école où les enfants, le plus souvent assis en face du maître, tiennent une lyre et s’efforcent de...

  20. 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...

  1. 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...

  2. Analyse fonctionnelle d’une alarme incendie

    OpenAIRE

    Jacob Dominique; Lagonotte Patrick

    2011-01-01

    L’enseignement de l’électricité dans les départements Hygiène Sécurité Environnement (HSE) des I.U.T. ne comprend qu’un faible nombre d’heures en première et en deuxième année. Il est cependant intéressant d’utiliser ce peu de temps à la présentation d’applications de l’électricité liées à la sécurité. Les alarmes incendie sont installées dans de très nombreux bâtiments recevant du public ou des travailleurs. Une alarme incendie est en général discrète et personne ne s’en préoccupe jusqu’au j...

  3. 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...

  4. Le fantastique roumain. une diachronie possible

    Directory of Open Access Journals (Sweden)

    Adriana Apostol

    2009-11-01

    Full Text Available Dans le présent aricle nous nous arrêtons sur le fantastique roumain au XIXe siècle, en tant que situation générique, et sur la possibilité d’une approche diachronique. Notre étude fait partie d’un projet plus ample des diachronies du fantastique dans deux espaces littéraires différents – en France et en Roumanie, à partir de la théorie de la réception : réception de deux étrangers, Hoffmann et Poe, en France, et réception des récits autochtones en Roumanie. Nous nous appuyons sur la démarche diachronique d’Ioan Vultur, qui identifie deux étapes dans l’apparition et l’évolution du fantastique roumain.

  5. Paralysie musculaire secondaire à une polymyosite

    Science.gov (United States)

    Ennafiri, Meryem; Elotmani, Wafae; Awab, Almahdi; El Moussaoui, Rachid; El Hijri, Ahmed; Alilou, Mustapha; Azzouzi, Abderrahim

    2015-01-01

    Les polymyosites sont des maladies inflammatoires des muscles striés, d’étiologie inconnue. Le déficit musculaire, qui se résume généralement à une fatigabilité, évolue de façon bilatérale, symétrique et non sélective avec prédominance sur les muscles proximaux. L'intensité de la faiblesse musculaire est variable d'un sujet à un autre, de la simple gêne fonctionnelle à un état grabataire. Nous rapportons l'observation d'un cas de polymyosite particulièrement sévère avec paralysie musculaire complète, touchant tous les muscles de l'organisme, d’évolution favorable sous immunoglobulines intraveineuses et nous discutons les facteurs favorisant la paralysie musculaire. PMID:26185559

  6. 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.

  7. 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

  8. 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...

  9. Skill forecasting from ensemble predictions of wind power

    DEFF Research Database (Denmark)

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

    2009-01-01

    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......Optimal management and trading of wind generation calls for the providing of uncertainty estimates along with the commonly provided short-term wind power point predictions. Alternative approaches for the use of probabilistic forecasting are introduced. More precisely, focus is given to prediction...... power 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...

  10. The role of Gibbs ensembles in statistical thermodynamics

    International Nuclear Information System (INIS)

    The motives are elucidated that force Gibbs to introduce the notion of ensemble when formulating the statistical thermodynamics. The term 'Gibbs ensemble' is analyzed in detail and its relation to the notion of probability is revealed. The examination of contemporary literature in pertaining field shows clearly that the term 'Gibbs ensemble' is used now only as a synonym of the statistical distribution function and nothing else. This implies, in particular, that the initial notion of the Gibbs ensemble, as the set of a large (more precisely, infinite) number of copies of the thermodynamical system under consideration, becomes now unnecessary in the mathematical tools of the statistical thermodynamics and when presenting its essentials, too. Furthermore, in its original meaning the term 'Gibbs ensemble' served in the last century only for definition of probability. Now a proper place of this term is presumably in interpretation of the statistical thermodynamics in a complete analogy as the quantum ensembles have been proposed for interpretation of quantum mechanics

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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

  17. Du Foro Bonaparte de Milan au Quartier du roi de Rome de Paris. Continuités et divergences d’une utopie républicaine à une vision impériale

    OpenAIRE

    Buclon, Romain

    2014-01-01

    En 1801, l’architecte Antolini vit son projet de Foro Bonaparte, prévu sur le site de l’ancienne citadelle de Milan, approuvé par le gouvernement provisoire cisalpin. Il s’agissait d’un immense ensemble de bâtiments à la gloire de Napoléon qui portait aussi un idéal « jacobin » de régénération et de célébration de la société italienne. Dix années plus tard, en 1811-1812, Napoléon planifia pour Paris une extension de grande envergure vers l’Ouest : le Quartier du roi de Rome. Ces deux projets ...

  18. 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...

  19. 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)

  20. 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. ...

  1. 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...

  2. The dynamics of exploitation in ensembles of source and sink

    OpenAIRE

    Friedrich, T.

    2012-01-01

    The ensemble is a new entity on a higher level of complexity composed of source and sink. When substrate is transferred from source to sink within the transfer space or the ensemble space non-linearity is observed. Saturating production functions of source and sink in combination with linear cost functions generate superadditivity and subadditivity in the productivity of the ensemble. In a reaction chain the source produces a product that will be used by the sink to produce a different pr...

  3. 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.

  4. 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 ...

  5. Mixture EMOS model for calibrating ensemble forecasts of wind speed

    OpenAIRE

    Baran, Sándor; Lerch, Sebastian

    2015-01-01

    Ensemble model output statistics (EMOS) is a statistical tool for post-processing forecast ensembles of weather variables obtained from multiple runs of numerical weather prediction models in order to produce calibrated predictive probability density functions (PDFs). The EMOS predictive PDF is given by a parametric distribution with parameters depending on the ensemble forecasts. We propose an EMOS model for calibrating wind speed forecasts based on weighted mixtures of truncated normal (TN)...

  6. Triality and the grand canonical ensemble in QCD

    International Nuclear Information System (INIS)

    QCD in the usual finite temperature formulation is using the grand canonical ensemble with chemical potential zero. We demonstrate that this description may give wrong predictions. QCD in the canonical formulation does not explicitly break Z(3) symmetry. It behaves in this sense like pure gluonic QCD. There are no metastable states in the canonical ensemble description as predicted in the grand canonical ensemble formalism. ((orig.))

  7. 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...

  8. Convergence of the Square Root Ensemble Kalman Filter in the Large Ensemble Limit

    Czech Academy of Sciences Publication Activity Database

    Kwiatkowski, E.; Mandel, Jan

    2015-01-01

    Roč. 3, č. 1 (2015), s. 1-17. ISSN 2166-2525 R&D Projects: GA ČR GA13-34856S Institutional support: RVO:67985807 Keywords : data assimilation * Lp laws of large numbers * Hilbert space * ensemble Kalman filter Subject RIV: IN - Informatics, Computer Science

  9. Forme atypique d'une maladie de Lyme

    Science.gov (United States)

    Mahfoudhi, Madiha; Turki, Sami; Kheder, Adel

    2015-01-01

    La maladie de Lyme est une zoonose qui se manifeste essentiellement par des signes cutanés, articulaires, neurologiques et cardiaques. Elle peut exceptionnellement mimer une dermatomyosite. Nous rapportons l'observation d'une patiente âgée de 37 ans qui a présenté des myalgies et un érythroedème de la face et en péri-orbitaire. Une dermatomyosite a été fortement suspectée devant une élévation des enzymes musculaires. Elle a été traitée par une corticothérapie à forte dose. L’évolution a été marquée par l'aggravation des myalgies et l'apparition d'un déficit musculaire. Elle a été alors hospitalisée dans notre service. Les enzymes musculaires étaient élevées. L’électromyogramme était sans anomalies. Le bilan immunologique était négatif. Une enquête infectieuse a été réalisée retrouvant une sérologie de Lyme positive. Après administration d'une antibiothérapie adaptée, l’évolution était bonne avec disparition du tableau clinico-biologique de dermatomyosite. La précocité du diagnostic et l'instauration d'un traitement efficace permet d’éviter des complications graves. PMID:26516401

  10. 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.

  11. Scénariser l’apprentissage, une activité de modélisation

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Pernin

    2007-01-01

    Full Text Available [Français] Un regard sur la scénarisation pédagogique: Depuis le début des années 2000, un ensemble de travaux de recherche et d’initiatives de terrain visent à proposer ou à utiliser des modèles, des méthodes et des outils pour concevoir, mettre en place, exploiter et analyser les scénarios d’apprentissage. Sur le plan international, on peut citer en particulier les travaux menés par Koper et Tattersall, (2005 portant sur les langages de modélisation pédagogique et plus spécifiquement autour de la proposition IMS (Instructional Management System Learning Design ainsi que ceux de Paquette (2006 conduisant à développer une approche en ingénierie éducative supportant le développement d’environnements d’apprentissage en ligne. Ces travaux ont contribué à faire émerger, au sein des communautés éducatives, le concept de scénario pédagogique comme un composant essentiel des systèmes d’apprentissage en ligne. Le but poursuivi par ces chercheurs et leurs équipes est « d’explorer comment améliorer la qualité pédagogique des cours en ligne, dans une voie interopérable, avec les outils d’usage facile ».

  12. 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.

  13. Ensemble atmospheric dispersion calculations for decision support systems

    International Nuclear Information System (INIS)

    This document describes two approaches to long-range atmospheric dispersion of pollutants based on the ensemble concept. In the first part of the report some experiences related to the exercises undertaken under the ENSEMBLE project of the European Union are presented. The second part is devoted to the implementation of mesoscale numerical prediction models RAMS and atmospheric dispersion model HYPACT on Beowulf cluster and theirs usage for ensemble forecasting and long range atmospheric ensemble dispersion calculations based on available meteorological data from NCEO, NOAA (USA). (author)

  14. 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.

  15. Une carte rupestre précolombienne? La modélisation des pétroglyphes mexicains

    Directory of Open Access Journals (Sweden)

    Véronique Darras

    1990-05-01

    Full Text Available Une carte rupestre précolombienne? L'analyse chorématique des pétroglyphes de Las Estacas (Zináparo, Michoacán, Mexique permet cette excitante hypothèse. La modélisation graphique révèle deux structures semi-concentriques opposées, différenciées par leur symbolique interne et associées par un ensemble de signes hiérarchisés et orientés. Nous l'interprétons comme la cartographie d'un événement social qui met en relation deux groupes culturels distincts mais complémentaires.

  16. 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...

  17. Du pilotage d'une famille de drones à celui d'un drone hybride via la commande adaptative

    OpenAIRE

    Ameho, Yann

    2013-01-01

    Les micro-drones sont des aéronefs sans pilotes de dimensions inférieures à un mètre et de poids inférieur à deux kilogrammes. Ils se distinguent des aéronefs classiques pour plusieurs raisons : un cycle de développement plus court, un coût plus faible, leur facilité d'opération et des configurations de véhicules spécifiques. L'ensemble de ces points attendent une réponse spécifique dans le développement des lois de commandes. Cette thèse s'y intéresse à travers deux problématiques : la comma...

  18. 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...

  19. 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.

  20. 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. ...

  1. Commande tolérante aux défauts : une approche basée sur la platitude

    OpenAIRE

    Martínez Torres, César

    2014-01-01

    L’objectif de ce manuscrit est de fournir une technique de commande tolérante aux défauts basée sur la platitude différentielle. Pour ce type de systèmes, il est possible de trouver un ensemble de variables, nommées sorties plates, tel que, les états et les entrées de commande du système puissent s’exprimer en fonction de ces sorties et d’un nombre fini de ses dérivées temporelles. Le bloc de détection et d’isolation doit assurer la détection du défaut le plus rapidement possible. Cette actio...

  2. Construction d'une ontologie du droit communautaire

    OpenAIRE

    Despres, Sylvie; Szulman, Sylvie

    2005-01-01

    Ce papier décrit une méthode de construction d'une ontologie du droit communautaire. La méthode repose sur la construction de micro-ontologies à partir de directives du droit communautaire en utilisant la méthode TERMINAE augmentée d'un processus d'alignement sur une ontologie générique du droit. L'ontologie est ensuite élaborée à l'aide d'un processus de fusion de micro-ontologies.

  3. Kigali : Une urbanisation entre modernisation et réconciliation

    OpenAIRE

    Michelon, Benjamin

    2008-01-01

    Considérée durant de nombreuses décennies comme une petite ville de province, Kigali comptait à peine 200 000 habitants avant le génocide de 1994. Avec plus de 850 000 habitants, c’est une véritable révolution urbaine que connait actuellement la capitale du Rwanda. Grâce à la construction de nombreux bâtiments modernes, Kigali change de visage, signe d’une réelle volonté politique d’effacer les stigmates du passé.

  4. Pratiques budgétaires : proposition d'une typologie

    OpenAIRE

    Sponem, Samuel; Lambert, Caroline

    2008-01-01

    L'objectif de cet article est de proposer une typologie des pratiques budgétaires afin de mieux comprendre les rôles que le budget remplit et les critiques qui peuvent lui être adressées. A partir d'une analyse classificatoire (taxinomie) des pratiques de 269 entreprises françaises et d'une analyse typologique, cinq styles budgétaires sont identifiés : le budget strict, le budget diagnostic, le budget interactif, le budget souple et le budget indicatif. Ces styles se distinguent principalemen...

  5. 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....

  6. 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.

  7. Reformulation of Ensemble Averages via Coordinate Mapping.

    Science.gov (United States)

    Schultz, Andrew J; Moustafa, Sabry G; Lin, Weisong; Weinstein, Steven J; Kofke, David A

    2016-04-12

    A general framework is established for reformulation of the ensemble averages commonly encountered in statistical mechanics. This "mapped-averaging" scheme allows approximate theoretical results that have been derived from statistical mechanics to be reintroduced into the underlying formalism, yielding new ensemble averages that represent exactly the error in the theory. The result represents a distinct alternative to perturbation theory for methodically employing tractable systems as a starting point for describing complex systems. Molecular simulation is shown to provide one appealing route to exploit this advance. Calculation of the reformulated averages by molecular simulation can proceed without contamination by noise produced by behavior that has already been captured by the approximate theory. Consequently, accurate and precise values of properties can be obtained while using less computational effort, in favorable cases, many orders of magnitude less. The treatment is demonstrated using three examples: (1) calculation of the heat capacity of an embedded-atom model of iron, (2) calculation of the dielectric constant of the Stockmayer model of dipolar molecules, and (3) calculation of the pressure of a Lennard-Jones fluid. It is observed that improvement in computational efficiency is related to the appropriateness of the underlying theory for the condition being simulated; the accuracy of the result is however not impacted by this. The framework opens many avenues for further development, both as a means to improve simulation methodology and as a new basis to develop theories for thermophysical properties. PMID:26950263

  8. 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.

  9. 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.

  10. Group theory for embedded random matrix ensembles

    Science.gov (United States)

    Kota, V. K. B.

    2015-04-01

    Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated quantum many-particle systems. For the simplest spinless fermion (or boson) systems with say m fermions (or bosons) in N single particle states and interacting with say k-body interactions, we have EGUE(k) [embedded GUE of k-body interactions) with GUE embedding and the embedding algebra is U(N). In this paper, using EGUE(k) representation for a Hamiltonian that is fc-body and an independent EGUE(t) representation for a transition operator that is t-body and employing the embedding U(N) algebra, finite-N formulas for moments up to order four are derived, for the first time, for the transition strength densities (transition strengths multiplied by the density of states at the initial and final energies). In the asymptotic limit, these formulas reduce to those derived for the EGOE version and establish that in general bivariate transition strength densities take bivariate Gaussian form for isolated finite quantum systems. Extension of these results for other types of transition operators and EGUE ensembles with further symmetries are discussed.

  11. 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...

  12. DINI Institutional Repository Certification and Beyond

    OpenAIRE

    Dobratz, Susanne

    2006-01-01

    Overview on certification of institutional repositories as a means to support Open Access in Germany and description of the DINI Certificate 2006 developed by DINI, the German Initiative for Networked Information. The DINI Certificate for Document and Publication Repositories shows potential users and authors of digital documents that a certain level of quality in operating the repository is guaranteed and that this distinguishes it from common institutional web servers. The Certificate ca...

  13. Is it time for rubberwood certification?

    OpenAIRE

    Noor Aini Zakaria; Lim Hin Fui; Ismariah Ahmad; Rohana Abd Rahman; Norliyana Adnan

    2012-01-01

    The increase in global attention on climate change, also heightens pressure on the implementation of certification on rubberwood plantation. Certification ensures that resources are managed sustainably for economic, environmental and societal benefits. The international push for rubberwood certification is an urgent issue as MalaysiaÕs furniture exporters are facing great pressure from the American and European markets. Some furniture buyers from Europe and America require certification espec...

  14. 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.

  15. 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

  16. Certification and the Branding of HRD

    Science.gov (United States)

    Carliner, Saul

    2012-01-01

    Although calls continue to establish certification, several certifications for human resource development (HRD) practitioners already exist, although none use the name HRD. This Forum explores what those certification programs are and what their availability means to the development of the HRD "brand" (the impressions of the service derived from…

  17. 34 CFR 34.21 - Employer certification.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Employer certification. 34.21 Section 34.21 Education Office of the Secretary, Department of Education ADMINISTRATIVE WAGE GARNISHMENT § 34.21 Employer certification. (a) Along with a garnishment order, we send to an employer a certification in a form...

  18. 46 CFR 109.439 - Crane certificates.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Crane certificates. 109.439 Section 109.439 Shipping... Reports, Notifications, and Records Records § 109.439 Crane certificates. The master or person in charge shall insure that the following certificates and records for each crane are maintained on the unit:...

  19. 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....

  20. 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...

  1. 75 FR 71454 - NIJ Certification Programs Workshop

    Science.gov (United States)

    2010-11-23

    ... of Justice Programs NIJ Certification Programs Workshop AGENCY: National Institute of Justice. ACTION: Notice of Meeting of the NIJ Certification Programs Workshop. SUMMARY: The National Institute of Justice (NIJ) is hosting a Certification Programs Workshop to introduce NIJ standards for law...

  2. 14 CFR 137.11 - Certificate required.

    Science.gov (United States)

    2010-01-01

    ... AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS AGRICULTURAL AIRCRAFT OPERATIONS Certification Rules § 137.11 Certificate required. (a) Except as provided in paragraphs (c) and (d) of this... dispensing of water on forest fires by rotorcraft external-load means, need not comply with this subpart....

  3. 29 CFR 1926.29 - Acceptable certifications.

    Science.gov (United States)

    2010-07-01

    ... Acceptable certifications. (a) Pressure vessels. Current and valid certification by an insurance company or... be in compliance with the requirements of this part when evidence of current and valid certification by an insurance company or regulatory authority attesting to the safe installation, inspection,...

  4. Minimalist ensemble algorithms for genome-wide protein localization prediction

    Directory of Open Access Journals (Sweden)

    Lin Jhih-Rong

    2012-07-01

    Full Text Available Abstract Background Computational prediction of protein subcellular localization can greatly help to elucidate its functions. Despite the existence of dozens of protein localization prediction algorithms, the prediction accuracy and coverage are still low. Several ensemble algorithms have been proposed to improve the prediction performance, which usually include as many as 10 or more individual localization algorithms. However, their performance is still limited by the running complexity and redundancy among individual prediction algorithms. Results This paper proposed a novel method for rational design of minimalist ensemble algorithms for practical genome-wide protein subcellular localization prediction. The algorithm is based on combining a feature selection based filter and a logistic regression classifier. Using a novel concept of contribution scores, we analyzed issues of algorithm redundancy, consensus mistakes, and algorithm complementarity in designing ensemble algorithms. We applied the proposed minimalist logistic regression (LR ensemble algorithm to two genome-wide datasets of Yeast and Human and compared its performance with current ensemble algorithms. Experimental results showed that the minimalist ensemble algorithm can achieve high prediction accuracy with only 1/3 to 1/2 of individual predictors of current ensemble algorithms, which greatly reduces computational complexity and running time. It was found that the high performance ensemble algorithms are usually composed of the predictors that together cover most of available features. Compared to the best individual predictor, our ensemble algorithm improved the prediction accuracy from AUC score of 0.558 to 0.707 for the Yeast dataset and from 0.628 to 0.646 for the Human dataset. Compared with popular weighted voting based ensemble algorithms, our classifier-based ensemble algorithms achieved much better performance without suffering from inclusion of too many individual

  5. 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...

  6. Syndrome de West: à propos d'une observation

    OpenAIRE

    Bugeme, Marcellin; Nawej, Pascal; Mukuku, Olivier

    2015-01-01

    Nous rapportons une observation d'un nourrisson de 7 mois présentant des spasmes infantiles et une microcéphalie. Elle était née à terme, en position de siège et avait présenté une asphyxie intrapartum (dépression néonatale) ayant conduit à une encéphalopathie néonatale modérée. Le diagnostic de Syndrome de West était confirmé à l’électroencéphalographie qui avait montré un tracé hypsarythmique. L'enfant avait été mise sous un traitement fait de Vigabatrine et son évolution était marquée par ...

  7. Dorothée, une machine pour récupérer le pétrole.

    CERN Multimedia

    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.

  8. 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 ».

  9. 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.

  10. Crossover ensembles of random matrices and skew-orthogonal polynomials

    International Nuclear Information System (INIS)

    Highlights: → We study crossover ensembles of Jacobi family of random matrices. → We consider correlations for orthogonal-unitary and symplectic-unitary crossovers. → We use the method of skew-orthogonal polynomials and quaternion determinants. → We prove universality of spectral correlations in crossover ensembles. → We discuss applications to quantum conductance and communication theory problems. - Abstract: In a recent paper (S. Kumar, A. Pandey, Phys. Rev. E, 79, 2009, p. 026211) we considered Jacobi family (including Laguerre and Gaussian cases) of random matrix ensembles and reported exact solutions of crossover problems involving time-reversal symmetry breaking. In the present paper we give details of the work. We start with Dyson's Brownian motion description of random matrix ensembles and obtain universal hierarchic relations among the unfolded correlation functions. For arbitrary dimensions we derive the joint probability density (jpd) of eigenvalues for all transitions leading to unitary ensembles as equilibrium ensembles. We focus on the orthogonal-unitary and symplectic-unitary crossovers and give generic expressions for jpd of eigenvalues, two-point kernels and n-level correlation functions. This involves generalization of the theory of skew-orthogonal polynomials to crossover ensembles. We also consider crossovers in the circular ensembles to show the generality of our method. In the large dimensionality limit, correlations in spectra with arbitrary initial density are shown to be universal when expressed in terms of a rescaled symmetry breaking parameter. Applications of our crossover results to communication theory and quantum conductance problems are also briefly discussed.

  11. 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…

  12. Programming in the Zone: Repertoire Selection for the Large Ensemble

    Science.gov (United States)

    Hopkins, Michael

    2013-01-01

    One of the great challenges ensemble directors face is selecting high-quality repertoire that matches the musical and technical levels of their ensembles. Thoughtful repertoire selection can lead to increased student motivation as well as greater enthusiasm for the music program from parents, administrators, teachers, and community members. Common…

  13. 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.

  14. Ensemble dispersion forecasting - Part 2. Application and evaluation

    DEFF Research Database (Denmark)

    Galmarini, S.; Bianconi, R.; Addis, R.; Andronopoulos, S.; Astrup, P.; Bartzis, J.C.; Bellasio, R.; Buckley, R.; Champion, H.; Chino, M.; D'Amours, R.; Davakis, E.; Eleveld, H.; Glaab, H.; Manning, A.; Mikkelsen, T.; Pechinger, U.; Polreich, E.; Prodanova, M.; Slaper, H.; Syrakov, D.; Terada, H.; Auwera, L. Van der

    2004-01-01

    The data collected during the long-range European tracer experiment (ETEX) conducted in 1994, are used to estimate quantitatively the ensemble dispersion concept presented in Part I. The modeling groups taking part to the ENSEMBLE activities (see, Part I) repeated model simulations of the...

  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. 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…

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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”.

  2. How to price imperfect certification

    Czech Academy of Sciences Publication Activity Database

    Mysliveček, Jan

    -, č. 364 (2008), s. 1-37. ISSN 1211-3298 R&D Projects: GA MŠk LC542 Grant ostatní: Univerzita Karlova(CZ) 7743/2007 Institutional research plan: CEZ:AV0Z70850503 Keywords : certification * imperfect testing * competition Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp364.pdf

  3. 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)

  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. Photon scattering from strongly driven atomic ensembles

    CERN Document Server

    Jin, Lu-ling; Macovei, Mihai

    2011-01-01

    The second order correlation function for light emitted from a strongly and near-resonantly driven dilute cloud of atoms is discussed. Because of the strong driving, the fluorescence spectrum separates into distinct peaks, for which the spectral properties can be defined individually. It is shown that the second-order correlations for various combinations of photons from different spectral lines exhibit bunching together with super- or sub-Poissonian photon statistics, tunable by the choice of the detector positions. Additionally, a Cauchy-Schwarz inequality is violated for photons emitted from particular spectral bands. The emitted light intensity is proportional to the square of the number of particles, and thus can potentially be intense. Three different averaging procedures to model ensemble disorder are compared.

  6. Ensemble based convergence assessment of biomolecular trajectories

    CERN Document Server

    Lyman, E; Lyman, Edward; Zuckerman, Daniel M.

    2006-01-01

    Assessing the convergence of a biomolecular simulation is an essential part of any computational investigation. This is because many important quantities (e.g., free energy differences) depend on the relative populations of different conformers; insufficient convergence translates into systematic errors. Here we present a simple method to self-consistently assess the convergence of a simulation. Standard clustering methods first generate a set of reference structures to any desired precision. The trajectory is then classified by proximity to the reference structures, yielding a one-dimensional histogram of structurally distinct populations. Comparing ensembles of different trajectories (or different parts of the same trajectory) built with the same reference structures provides a sensitive, quantitative measure of convergence. Please note: this is a preliminary manuscript, and should be read as such. Comments are most welcome, especially regarding pertinent prior work.

  7. Ensemble Kalman Filtering without a Model

    Science.gov (United States)

    Hamilton, Franz; Berry, Tyrus; Sauer, Timothy

    2016-01-01

    Methods of data assimilation are established in physical sciences and engineering for the merging of observed data with dynamical models. When the model is nonlinear, methods such as the ensemble Kalman filter have been developed for this purpose. At the other end of the spectrum, when a model is not known, the delay coordinate method introduced by Takens has been used to reconstruct nonlinear dynamics. In this article, we merge these two important lines of research. A model-free filter is introduced based on the filtering equations of Kalman and the data-driven modeling of Takens. This procedure replaces the model with dynamics reconstructed from delay coordinates, while using the Kalman update formulation to reconcile new observations. We find that this combination of approaches results in comparable efficiency to parametric methods in identifying underlying dynamics, and may actually be superior in cases of model error.

  8. 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

  9. 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.

  10. 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...

  11. Maladie de Takayasu et polyarthrite rhumatoïde: une association rare - à propos d'une observation

    OpenAIRE

    Frikha, Faten; Maazoun, Fatma; Snoussi, Mouna; Abid, Leila; Abid, Hanen; Bouassida, Walid; Kaddour, Neila; Bahloul, Zouhir

    2012-01-01

    L'artérite de Takayasu ou maladie de Takayasu (MT) et la polyarthrite rhumatoïde (PR) et sont deux maladies inflammatoires chroniques et leur association a été rapportée dans la littérature à travers quelques observations de cas sporadiques. Nous rapportons une nouvelle observation d'une telle association. Une patiente âgée de 44 ans, diagnostiquée avec une polyarthrite rhumatoïde à facteur rhumatoïde positif, qui a développé des céphalées avec des vertiges de caractère permanent. L'examen ré...

  12. 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.

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

    International Nuclear Information System (INIS)

    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, is derived. Exact conditions that are proven include the signs of the correlation energy components 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

  14. Induced Ginibre ensemble of random matrices and quantum operations

    International Nuclear Information System (INIS)

    A generalization 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 quadratization procedure. We derive the joint probability density of eigenvalues for such an 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 the statistical properties of evolution operators associated with random quantum operations for which the dimensions of the input state and the output state do differ. (paper)

  15. 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.

  16. 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.

  17. Planetary Protection Alternate Protocol Certification

    Science.gov (United States)

    Baker, Amy; Barengoltz, Jack; Tisdale, David

    The talk presents a standardized approach for new method certification or alterative testing protocol (ATP) certification against the existing U.S. Planetary Protection Standards. In consideration of new method certification there are two phases of activities that are relevant to the certification process. The first is sample acquisition which typically incorporates swab or wipes sampling on relevant hardware, associated facilities and ground support equipment. The sampling methods introduce considerations of field sampling efficiency as it relates to spore distribution on the spacecraft, spacecraft material influences on the ability of the swab or wipe to remove spores from the hardware, the types of swabs and wipes used (polyester, cotton, macrofoam), and human sampling influences. The second portion of a new protocol certification looks specifically at the lab work-up or analysis of the samples provided to the laboratory. Variables in this process include selection of appropriate biomarkers, extraction efficiencies (removal of spores or constituents of interest from the sampling device), and a method's ability to accurately determine the number of spores present in the sample with a statistically valid level of confidence as described by parameters such as precision, accuracy, robustness, specificity and sensitivity. Considerations for alternative testing protocols such as those which utilize bioburden reduction techniques include selection of appropriate biomarkers for testing, test materials and a defined statistical approach that provides sufficient scientific data to support the modification of an existing NASA specification or the generation of a new NASA specification. Synergies between the U.S. and European Space Agency approaches will also be discussed.

  18. Environmental certificate to Salmisaari plants

    International Nuclear Information System (INIS)

    SFS-EN ISO 14001 certificate has been granted in October 2nd 2000 to the environmental systems of Salmisaari power plant area owned by Helsinki Energia. The certificate cowers power and district heat generation at the power plants of the Salmisaari area. The certified system will be used as the basis for the future environmental work. Salmisaari B is a combined heat and power plant, and Salmisaari A is a boiler plant generating district heat for use in winter. Both plants use coal as main fuel. Dusts and sulphur compounds are removed from the flue gases formed in combustion in desulphurisation plant. Development of the environmental system started in autumn 1997 by excursion to acquaint the environmental system of the Rauhalahti power plant. Development work started in spring 1998. External evaluations and the recording of the present situation by DNV (Det Norske Veritas) consulting services were carried out at the end of 1999. The inspection of the management was carried out in the beginning of 2000 and the auditing was made in May 2000. Auditing showed about ten faults or lacks in the system, which were repaired. DNV Certification Oy/AB carried out the certification. Certification granted in the beginning of October 2000, covers power and district heat generation of the Salmisaari plants, as well as all the operations and systems, such as power station, underground oil storages, coal storage and the Tammasaari coal and oil unloading docks and Kellosaari power plants, connected to them. Desulphurisation plant of Salmisaari has operated since 1987, and NOx emissions have been reduced since 1991 by improved coal combustion system. In Hanasaari power plant the combustion technology was renewed during reduction of NOx emissions in 1994

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

    OpenAIRE

    Halu, Arda; Mukherjee, Satyam; 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 ...

  20. Une lecture possible du territoire Sophipolitain : l'observation des représentations virtuelles d'une technopole

    OpenAIRE

    Bertacchini, Yann; Boutin, Eric

    2003-01-01

    Nous rappelerons dans un premier temps les caractéritiques d'un territoire et préciserons le plan des relations qui forment la territorialité. Dans une seconde partie, nous nous intéresserons à la dimension normative pour ce qui caractérise les objets virtuels. Nous conduirons une démarche de veille territoriale appliquée à la technopole de Sophia Antipolis.

  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. 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...

  3. 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.

  4. Assessing the impact of land use change on hydrology by ensemble modelling (LUCHEM) II: Ensemble combinations and predictions

    Science.gov (United States)

    Viney, N.R.; Bormann, H.; Breuer, L.; Bronstert, A.; Croke, B.F.W.; Frede, H.; Graff, T.; Hubrechts, L.; Huisman, J.A.; Jakeman, A.J.; Kite, G.W.; Lanini, J.; Leavesley, G.; Lettenmaier, D.P.; Lindstrom, G.; Seibert, J.; Sivapalan, M.; Willems, P.

    2009-01-01

    This paper reports on a project to compare predictions from a range of catchment models applied to a mesoscale river basin in central Germany and to assess various ensemble predictions of catchment streamflow. The models encompass a large range in inherent complexity and input requirements. In approximate order of decreasing complexity, they are DHSVM, MIKE-SHE, TOPLATS, WASIM-ETH, SWAT, PRMS, SLURP, HBV, LASCAM and IHACRES. The models are calibrated twice using different sets of input data. The two predictions from each model are then combined by simple averaging to produce a single-model ensemble. The 10 resulting single-model ensembles are combined in various ways to produce multi-model ensemble predictions. Both the single-model ensembles and the multi-model ensembles are shown to give predictions that are generally superior to those of their respective constituent models, both during a 7-year calibration period and a 9-year validation period. This occurs despite a considerable disparity in performance of the individual models. Even the weakest of models is shown to contribute useful information to the ensembles they are part of. The best model combination methods are a trimmed mean (constructed using the central four or six predictions each day) and a weighted mean ensemble (with weights calculated from calibration performance) that places relatively large weights on the better performing models. Conditional ensembles, in which separate model weights are used in different system states (e.g. summer and winter, high and low flows) generally yield little improvement over the weighted mean ensemble. However a conditional ensemble that discriminates between rising and receding flows shows moderate improvement. An analysis of ensemble predictions shows that the best ensembles are not necessarily those containing the best individual models. Conversely, it appears that some models that predict well individually do not necessarily combine well with other models in

  5. 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

  6. 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

  7. 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.

  8. Analyse de la richesse piscicole de quatre ensembles hydrographiques français

    Directory of Open Access Journals (Sweden)

    PONT D.

    1995-04-01

    Full Text Available L'analyse des variations de richesse en espèces piscicoles autochtones le long des gradients longitudinaux de quatre ensembles hydrographiques français met en évidence un accroissement amont-aval similaire par type de bassins (grands bassins de la Seine et du Rhône et fleuves côtiers breton et du Languedoc-Roussillon. Les richesses spécifiques sont comparables à l'amont (0 à 4 km de la source et diffèrent significativement plus en aval. Dans les deux grands bassins, la pente est le premier facteur explicatif de la variation de la richesse en espèces autochtones, suivi de la distance à la source, de l'altitude et de la largeur. A une échelle d'espace supérieure, le positionnement géographique (latitude n'a pas d'effet significatif. Dans ces bassins, la richesse en espèces autochtones serait d'abord régulée par les conditions prévalant aux échelles locales et de la zonation.

  9. 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.

  10. 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

  11. 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.

  12. Stochastic dynamics simulations in a new generalized ensemble

    CERN Document Server

    Hansmann, Uwe H E; Okamoto, Y; Hansmann, Ulrich H.E.; Eisenmenger, Frank; Okamoto, Yuko

    1998-01-01

    We develop a formulation for molecular dynamics, Langevin, and hybrid Monte Carlo algorithms in the recently proposed generalized ensemble that is based on a physically motivated realisation of Tsallis weights. The effectiveness of the methods are tested with an energy function for a protein system. Simulations in this generalized ensemble by the three methods are performed for a penta peptide, Met-enkephalin. For each algorithm, it is shown that from only one simulation run one can not only find the global-minimum-energy conformation but also obtain probability distributions in canonical ensemble at any temperature, which allows the calculation of any thermodynamic quantity as a function of temperature.

  13. Quantum storage based on collective excitations in atomic ensemble

    International Nuclear Information System (INIS)

    The authors reviews a new protocol of quantum memory based on the quasi-pin wave excitation of the Λ systems fixed the sites of lattice. This protocol tries to avoid the disadvantage of the quantum memory scheme based on free atom ensemble, the quantum decoherence induced by the quantum leakage of collective state. Especially, authors discover a universal dynamic symmetry hidden in various ensemble based quantum storage scheme. To understand the significance of this work exactly, authors also give a brief introduction to our systematical studies on collective symmetric excitons in quantum ensemble, which is the necessary to propose the present scheme for quantum memory. (author)

  14. 21 CFR 80.37 - Treatment of batch pending certification.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Treatment of batch pending certification. 80.37... COLOR ADDITIVE CERTIFICATION Certification Procedures § 80.37 Treatment of batch pending certification. Immediately after the sample that is to accompany a request for certification of a batch of color additive...

  15. 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...

  16. 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...

  17. 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...

  18. 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,...

  19. 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.

  20. Forest Certification: Toward Common Standards?

    OpenAIRE

    Fischer, Carolyn; Sedjo, Roger; Jawahar, Puja; Aguilar, Francisco

    2005-01-01

    The forestry industry provides a good illustration of the active roles that industry associations, environmental nongovernmental organizations (NGOs), national governments, and international organizations can play in developing and promoting codes of conduct that are formally sanctioned and certified. It also reflects some of the challenges of disseminating codes of conduct in developing countries and ensuring market benefits from certification. We describe the emergence of forest certificati...

  1. 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...

  2. Thermodynamic indicators for environmental certification.

    Science.gov (United States)

    Panzieri, Margherita; Porcelli, Marcello; Pulselli, Federico Maria

    2002-09-01

    The Earth is an open thermodynamic system, that remains in a steady state far from the equilibrium, through energy and matter exchanges with the surrounding environment. These natural constraints, which prevent the system from maximizing its entropy, are threatened by human action and our ecosystem needs urgent protection. In this viewpoint the environmental certification was born, according to international standards ISO 14001, ISO 14040, and European Regulation EMAS. These are voluntary adhesions to a program of environmental protection by companies, administrations and organizations which, starting from the respect of the existing environmental laws and regulations, decide to further improve their environmental performance. To obtain and maintain certification of a system is necessary to apply some indicators to evaluate its environmental performance and to demonstrate its progressive improvement. Here we propose to use for this purpose the thermodynamic indicators produced from energy analysis by Odum. The case study is Montalcino city (Italy) and energy indicators are used to evaluate environmental performance of this system where exist different activities, from agricultural productions, to tourism. Results show that energy analysis could become a valid standard monitoring method for environmental certification, especially in consideration of its wide application field. PMID:12407910

  3. 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.

  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. 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.

  7. 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.

  8. Misusability Weight Measure Using Ensemble Approaches

    Directory of Open Access Journals (Sweden)

    Sridevi Sakhamuri1 V.Ramachandran 2 Dr.Rupa

    2013-09-01

    Full Text Available Assigning a misusability weight to a given dataset is strongly related to the way the data is presented (e.g., tabular data, structured or free text and is domain specific. Therefore, one measure of misusability weight cannot fit all types of data in every domain but it gives a fair idea on how to proceed to handle sensitive data. Previous approaches such as M-score models that consider number of entities, anonymity levels, number of properties and values of properties to estimate misusability value for a data record has better efficiency in deducting record sensitivities. Quality of data, Quantity data, and the distinguishing attributes are vital factors that can influence Mscore. Combined with record ranking and knowledge models prior Approaches used one domain expert for deducting sensitive information. But for better performance and accuracy we propose to use the effect of combining knowledge from several experts (e.g., ensemble of knowledge models. Also we plan to extend the computations of sensitivity level of sensitive attributes to be objectively obtained by using machine learning techniques such as SVM classifier along with expert scoring models. This approach particularly fits the sensitive parameter values to the customer value based on customer activity which is far more efficient compared to face value specification with human involvement. A practical implementation of the proposed system validates our claim.

  9. 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.

  10. Group Theory for Embedded Random Matrix Ensembles

    CERN Document Server

    Kota, V K B

    2014-01-01

    Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated quantum many-particle systems. For the simplest spinless fermion (or boson) systems with say $m$ fermions (or bosons) in $N$ single particle states and interacting with say $k$-body interactions, we have EGUE($k$) [embedded GUE of $k$-body interactions) with GUE embedding and the embedding algebra is $U(N)$. In this paper, using EGUE($k$) representation for a Hamiltonian that is $k$-body and an independent EGUE($t$) representation for a transition operator that is $t$-body and employing the embedding $U(N)$ algebra, finite-$N$ formulas for moments up to order four are derived, for the first time, for the transition strength densities (transition strengths multiplied by the density of states at the initial and final energies). In the asymptotic limit, these formulas reduce to those derived for the EGOE version and establish that in general bivariate transition strength densities take bivariate Gaussian ...

  11. 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

  12. Quantum metrology with cold atomic ensembles

    Directory of Open Access Journals (Sweden)

    Mitchell Morgan W.

    2013-08-01

    Full Text Available Quantum metrology uses quantum features such as entanglement and squeezing to improve the sensitivity of quantum-limited measurements. Long established as a valuable technique in optical measurements such as gravitational-wave detection, quantum metrology is increasingly being applied to atomic instruments such as matter-wave interferometers, atomic clocks, and atomic magnetometers. Several of these new applications involve dual optical/atomic quantum systems, presenting both new challenges and new opportunities. Here we describe an optical magnetometry system that achieves both shot-noise-limited and projection-noise-limited performance, allowing study of optical magnetometry in a fully-quantum regime [1]. By near-resonant Faraday rotation probing, we demonstrate measurement-based spin squeezing in a magnetically-sensitive atomic ensemble [2-4]. The versatility of this system allows us also to design metrologically-relevant optical nonlinearities, and to perform quantum-noise-limited measurements with interacting photons. As a first interaction-based measurement [5], we implement a non-linear metrology scheme proposed by Boixo et al. with the surprising feature of precision scaling better than the 1/N “Heisenberg limit” [6].

  13. Ensemble Kalman filtering with residual nudging

    CERN Document Server

    Luo, Xiaodong; 10.3402/tellusa.v64i0.17130

    2012-01-01

    Covariance inflation and localization 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/o...

  14. Cluster ensembles, quantization and the dilogarithm

    DEFF Research Database (Denmark)

    Fock, Vladimir; Goncharov, Alexander B.

    2009-01-01

    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......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...... 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...

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

    Science.gov (United States)

    Thirel, G.; Martin, E.; Mahfouf, J.-F.; Massart, S.; Ricci, S.; Regimbeau, F.; Habets, F.

    2010-08-01

    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 Rate, etc

  16. 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

  17. 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.

  18. Game Analysis of Policy for Forest Certification

    OpenAIRE

    Guan Zhi-Jie; Cao Jian-Hua

    2013-01-01

    Forest certification is promoting sustainable managed forest, it has become an excellent tool for forestry products green procurement and it prevented the illegal logging and purchasing effectively. Forest certification makes the forestry enterprise add the more cost and reduces its profit. Forest certification meets the need of sustainable development due to the important role of forest in the society and enlarges the certified product’s market in an envir...

  19. 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...

  20. 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...

  1. 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...

  2. Évolution et persistance d’une condamnation antique

    OpenAIRE

    Gabay, Simon

    2012-01-01

    Est-ce que l’histrion, malgré sa pratique illicite, peut être payé ? Recevoir ou donner l’aumône ? Faire une offrande ? Payer la dîme ? Sa capacité économique est disséquée par les théologiens et les juristes médiévaux, qui la font évoluer lentement vers une plus grande tolérance jusqu’à son apparente réhabilitation par Thomas d’Aquin. Apparente cependant, car cette première évolution est contrebalancée par la persistance d’une pensée plus traditionaliste, notamment au sein de l’Église concer...

  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. Sécurisation d'une Passerelle XML - SNMP

    OpenAIRE

    Collet, Laurent; Cridlig, Vincent

    2004-01-01

    Ce rapport présente l'implémentation d'extensions de sécurité pour une passerelle XML/SNMP. Le travail effectué se base sur une implémentation existante d'une telle passerelle et y ajoute des fonctionnalités pour établir un "continuum" de sécurité depuis les administrateurs réseaux jusqu'aux agents SNMP. Plusieurs mécanismes de sécurité ont été ajoutés : contrôle d'accès basé sur les rôles, authentification et confidentialité.

  5. 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.

  6. 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.

  7. Protein Remote Homology Detection Based on an Ensemble Learning Approach

    Science.gov (United States)

    Chen, Junjie; Liu, Bingquan; Huang, Dong

    2016-01-01

    Protein remote homology detection is one of the central problems in bioinformatics. Although some computational methods have been proposed, the problem is still far from being solved. In this paper, an ensemble classifier for protein remote homology detection, called SVM-Ensemble, was proposed with a weighted voting strategy. SVM-Ensemble combined three basic classifiers based on different feature spaces, including Kmer, ACC, and SC-PseAAC. These features consider the characteristics of proteins from various perspectives, incorporating both the sequence composition and the sequence-order information along the protein sequences. Experimental results on a widely used benchmark dataset showed that the proposed SVM-Ensemble can obviously improve the predictive performance for the protein remote homology detection. Moreover, it achieved the best performance and outperformed other state-of-the-art methods. PMID:27294123

  8. 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.

  9. Ensemble-based Probabilistic Forecasting at Horns Rev

    DEFF Research Database (Denmark)

    Pinson, Pierre; Madsen, Henrik

    2009-01-01

    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 are...... then converted into predictive distributions with an original adaptive kernel dressing method. The shape of the kernels is driven by a mean-variance model, the parameters of which ore recursively estimated in order to maximize the overall skill of obtained predictive distributions. Such a methodology...

  10. Average Stopping Set Weight Distribution of Redundant Random Matrix Ensembles

    CERN Document Server

    Wadayama, Tadashi

    2007-01-01

    In this paper, redundant random matrix ensembles (abbreviated as redundant random ensembles) are defined and their stopping set (SS) weight distributions are analyzed. A redundant random ensemble consists of a set of binary matrices with linearly dependent rows. These linearly dependent rows (redundant rows) significantly reduce the number of stopping sets of small size. An upper and lower bound on the average SS weight distribution of the redundant random ensembles are shown. From these bounds, the trade-off between the number of redundant rows (corresponding to decoding complexity of BP on BEC) and the critical exponent of the asymptotic growth rate of SS weight distribution (corresponding to decoding performance) can be derived. It is shown that, in some cases, a dense matrix with linearly dependent rows yields asymptotically (i.e., in the regime of small erasure probability) better performance than regular LDPC matrices with comparable parameters.

  11. 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...

  12. Low energy level spacing distribution in the atomic table ensemble

    International Nuclear Information System (INIS)

    We have analysed the nearest neighbour spacing distributions for the atomic table ensemble. The analysis carried out indicates that the random matrix theory arguments extend even to the ground state domain of atoms. (orig.)

  13. Inter-comparison study of the ENSEMBLE project

    International Nuclear Information System (INIS)

    During the days of the Chernobyl accident, the European national long-range dispersion forecasts would differ because of differences in national models, and differences in weather prediction methods. ENSEMBLE project was launched for a reconciliation and harmonization of the disparate long-range dispersion forecasts. Responsible European emergency organizations in addition to Canadian, Japanese, Korean and US agencies have participated in ENSEMBLE. KAERI joined the inter-comparison study for the exercise on the 901-001 scenario in ENSEMBLE. KAERI was assigned KR1 as a national code and 53 as a model number. The model of KAERI was compared with the other models of the participants in ENSEMBLE. The comparative results are presented with the scatter plots and statistical methods in this paper. (author)

  14. 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.

  15. Level repulsion in constrained Gaussian random-matrix ensembles

    International Nuclear Information System (INIS)

    Introducing sets of constraints, we define new classes of random-matrix ensembles, the constrained Gaussian unitary (CGUE) and the deformed Gaussian unitary (DGUE) ensembles. The latter interpolate between the GUE and the CGUE. We derive a sufficient condition for GUE-type level repulsion to persist in the presence of constraints. For special classes of constraints, we extend this approach to the orthogonal and to the symplectic ensembles. A generalized Fourier theorem relates the spectral properties of the constraining ensembles with those of the constrained ones. We find that in the DGUEs, level repulsion always prevails at a sufficiently short distance and may be lifted only in the limit of strictly enforced constraints

  16. Level repulsion in constrained Gaussian random-matrix ensembles

    Science.gov (United States)

    Papenbrock, T.; Pluhar, Z.; Weidenmüller, H. A.

    2006-08-01

    Introducing sets of constraints, we define new classes of random-matrix ensembles, the constrained Gaussian unitary (CGUE) and the deformed Gaussian unitary (DGUE) ensembles. The latter interpolate between the GUE and the CGUE. We derive a sufficient condition for GUE-type level repulsion to persist in the presence of constraints. For special classes of constraints, we extend this approach to the orthogonal and to the symplectic ensembles. A generalized Fourier theorem relates the spectral properties of the constraining ensembles with those of the constrained ones. We find that in the DGUEs, level repulsion always prevails at a sufficiently short distance and may be lifted only in the limit of strictly enforced constraints.

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. Radiation protection supervisors certification in Brazil

    International Nuclear Information System (INIS)

    In order to accomplish its legal assignments CNEN certifies the qualification of radiation protection supervisors. The current certification process is presented and discussed in this paper. This paper discusses the main points of the certification process including: knowledge tests, stake holder's communication, standards, supervisor responsibilities and profiles. The importance of safety certification of nuclear facilities and radiation protection of public individuals and workers are also discussed. Taking into account the characteristics of the Brazilian Nuclear program, the future improvements and goals in the certification process is also presented. (author)

  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. Establishing EPR-channels between Nanomechanics and Atomic Ensembles

    OpenAIRE

    Hammerer, K.; Aspelmeyer, M.; Polzik, E. S.; Zoller, P.

    2008-01-01

    We suggest to interface nanomechanical systems via an optical quantum bus to atomic ensembles, for which means of high precision state preparation, manipulation and measurement are available. This allows in particular for a Quantum Non-Demolition Bell measurement, projecting the coupled system, atomic ensemble - nanomechanical resonator, into an entangled EPR-state. The entanglement is observable even for nanoresonators initially well above their ground states and can be utilized for teleport...

  4. 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 ...

  5. Bayesian Tracking of Emerging Epidemics Using Ensemble Optimal Statistical Interpolation

    OpenAIRE

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

    2014-01-01

    We present a preliminary test of the Ensemble Optimal Statistical Interpolation (EnOSI) method for the statistical tracking of an emerging epidemic, with a comparison to its popular relative for Bayesian data assimilation, the Ensemble Kalman Filter (EnKF). The spatial data for this test was generated by a spatial susceptible-infectious-removed (S-I-R) epidemic model of an airborne infectious disease. Both tracking methods in this test employed Poisson rather than Gaussian noise, so as to han...

  6. Defining critical thresholds for ensemble flood forecasting and warning

    OpenAIRE

    Weeink, Werner H.A.; Ramos, Maria-Helena; Booij, Martijn J.; Andreassian, Vazken; Maarten S. Krol

    2010-01-01

    The use of weather ensemble predictions in ensemble flood forecasting is an acknowledged procedure to include the uncertainty of meteorological forecasts in a probabilistic streamflow prediction system. Operational flood forecasters can thus get an overview of the probability of exceeding a critical discharge or water level, and decide on whether a flood warning should be issued or not. This process offers several challenges to forecasters: 1) how to define critical thresholds along all the r...

  7. 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 ...

  8. Generalized Gibbs canonical ensemble: A possible physical scenario

    OpenAIRE

    Velazquez, L.

    2007-01-01

    After reviewing some fundamental results derived from the introduction of the generalized Gibbs canonical ensemble, such as the called thermodynamic uncertainty relation, it is described a physical scenario where such a generalized ensemble naturally appears as a consequence of a modification of the energetic interchange mechanism between the interest system and its surrounding, which could be relevant within the framework of long-range interacting systems.

  9. 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)

  10. Ensemble averaging applied to the flow of a multiphase mixture

    International Nuclear Information System (INIS)

    Ensemble averaging theorems are used to derive a two-fluid model describing the flow of a dilute fluid-solid mixture. The model is valid for mixtures containing particles that are small compared to the length scales describing variations in ensemble-averaged field quantities, such as fluid or particle phase density, pressure or velocity. For the case where the mixture is pseudo-homogeneous, the equations obtained reproduce the Einstein viscosity correction

  11. 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.

  12. Sampling the isothermal-isobaric ensemble by Langevin dynamics

    OpenAIRE

    Gao, Xingyu; Fang, Jun; Wang, Han

    2016-01-01

    We present a new method of conducting molecular dynamics simulation in isothermal-isobaric ensemble based on Langevin equations of motion. The stochastic coupling to all particle and cell degrees of freedoms is introduced in a correct way, in the sense that the stationary configurational distribution is proved to be in consistent with that of the isothermal-isobaric ensemble. In order to apply the proposed method in computer simulations, a second order symmetric numerical integration scheme i...

  13. Scalable Ensemble Learning and Computationally Efficient Variance Estimation

    OpenAIRE

    LeDell, Erin

    2015-01-01

    Ensemble machine learning methods are often used when the true prediction function is not easily approximated by a single algorithm. The Super Learner algorithm is an ensemble method that has been theoretically proven to represent an asymptotically optimal system for learning. The Super Learner, also known as stacking, combines multiple, typically diverse, base learning algorithms into a single, powerful prediction function through a secondary learning process called metalearning. Although...

  14. 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...

  15. Routines organisationnelles : vers une perspective communicationnelle

    OpenAIRE

    Wright, Alex

    2014-01-01

    Comment l’organizing routinier est-il accompli? Selon des approches récentes, les routines devraient être comprises comme dynamiques plutôt que statiques. Bien que cette tendance s’avère utile, elle est basée sur une lecture erronée des notions d’ostentif et de performatif telle que développées par Latour (1986). Je remets en cause cette interprétation, inspirée de la théorie de la structuration, et je propose une conceptualisation alternative basée sur la perspective de la communication orga...

  16. 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...

  17. 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...

  18. Une théorisation communicationnelle et documentaire des TIC

    OpenAIRE

    Zacklad, Manuel

    2007-01-01

    Dans ce chapitre nous proposerons une analyse communicationnelle et documentaire des TIC elle-même inscrite dans le cadre de l'Analyse Transactionnelle de l'Action. Cette vision documentaire présente selon nous un double avantage. D'une part, elle nous permet de nous décentrer de la vision technique pour nous focaliser sur les usages et les pratiques qui, pour la plupart, sont en continuité des usages et des pratiques documentaires qui préexistaient à l'informatisation même si cette dernière ...

  19. 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, ...

  20. 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 ...

  1. 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...

  2. Appropriation de l’innovation et coopération des firmes françaises : une étude empirique sur les données de CIS3

    OpenAIRE

    Gallaud, Delphine; Nayaradou, Maximilien

    2011-01-01

    Dans le cadre des coopérations pour innover, le brevet a toujours eu plus d’importance pour les entreprises que les autres moyens d’appropriation, car il permet de clarifier les droits de propriété de chacun des partenaires (Cassiman, Veugelers, 2002). Cependant, les travaux effectués ont rarement analysé l’ensemble des moyens d’appropriation dont disposent les entreprises dans les accords de coopération, préférant en général se limiter à une opposition entre le secret et le brevet. Hertzfel...

  3. 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

  4. Ensemble forecasting of major solar flares: First results

    Science.gov (United States)

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

    2015-10-01

    We present the results from the first ensemble prediction model for major solar flares (M and X classes). The primary aim of this investigation is to explore the construction of an ensemble for an initial prototyping of this new concept. 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 Pth to the combined probabilities and maximizing the Heidke Skill Score (HSS). Using the data for 13 recent solar active regions between years 2012 and 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 Pth. 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 Pth 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.

  5. 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.

  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. Ensembles of a small number of conformations with relative populations

    International Nuclear Information System (INIS)

    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

  8. Effects of ensembles on methane hydrate nucleation kinetics.

    Science.gov (United States)

    Zhang, Zhengcai; Liu, Chan-Juan; Walsh, Matthew R; Guo, Guang-Jun

    2016-06-21

    By performing molecular dynamics simulations to form a hydrate with a methane nano-bubble in liquid water at 250 K and 50 MPa, we report how different ensembles, such as the NPT, NVT, and NVE ensembles, affect the nucleation kinetics of the methane hydrate. The nucleation trajectories are monitored using the face-saturated incomplete cage analysis (FSICA) and the mutually coordinated guest (MCG) order parameter (OP). The nucleation rate and the critical nucleus are obtained using the mean first-passage time (MFPT) method based on the FS cages and the MCG-1 OPs, respectively. The fitting results of MFPT show that hydrate nucleation and growth are coupled together, consistent with the cage adsorption hypothesis which emphasizes that the cage adsorption of methane is a mechanism for both hydrate nucleation and growth. For the three different ensembles, the hydrate nucleation rate is quantitatively ordered as follows: NPT > NVT > NVE, while the sequence of hydrate crystallinity is exactly reversed. However, the largest size of the critical nucleus appears in the NVT ensemble, rather than in the NVE ensemble. These results are helpful for choosing a suitable ensemble when to study hydrate formation via computer simulations, and emphasize the importance of the order degree of the critical nucleus. PMID:27222203

  9. 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.

  10. 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.

  11. Hierarchical ensemble-based data fusion for structural health monitoring

    International Nuclear Information System (INIS)

    In structural health monitoring, damage detection results always have uncertainty because of three factors: measurement noise, modeling error and environment changes. Data fusion can lead to the improved accuracy of a classification decision as compared to a decision based on any individual data source alone. Ensemble approaches constitute a relatively new breed of algorithms used for data fusion. In this paper, we introduced a hierarchical ensemble scheme to the data fusion field. The hierarchical ensemble scheme was based on the Dempster–Shafer (DS) theory and the Rotation Forest (RF) method, it was called a hierarchical ensemble because the RF method itself was an ensemble method. The DS theory was used to combine the output of RF based on different data sources. The validation accuracy of the RF model was considered in the improvement of the performance of the hierarchical ensemble. Health monitoring of a small-scale two-story frame structure with different damages subject to shaking table tests was used as an example to validate the efficiency of the proposed scheme. The experimental results indicated that the proposed scheme will improve the identification accuracy and increase the reliability of identification

  12. 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.

  13. 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.

  14. 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.

  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. 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

  17. 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.

  18. 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

  19. 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

  20. How Consumers use Gift Certificates

    OpenAIRE

    Felso, Flora; Adriaan R. Soetevent

    2012-01-01

    This discussion paper resulted in the article Broad and Narrow Bracketing in Gift Certificate Spending in the 'European Economic Review' (2014). Volume 66, pages 284-302. We survey 1,050 consumers who have just redeemed one or more open loop gift certicates to learn whether they view gift certicate income, cash gifts and non-gift income as substitutes. We find that the majority (83%) of recipients spends the certicates in the same way as cash. The other respondents (17%) bought an item they w...