Description de l'architecture Scilab pour le projet RNTL/OMD

http://www.emse.fr/~leriche/OMD_spec_scilab_march2008.pdfLes algorithmes d'optimisation classiques sont impl'ement'es selon un paradigme fonctionnel qui place la m'ethode d'optimisation au sommet de la hi'erarchie. Par exemple, avec Scilab on 'ecrira la commande [f,xopt]=optim(costf,x0). Cette instruction se chargera de tout le processus d'optimisation, sans contrˆole possible de l'utilisateur. Ce type d'impl'ementation est tr'es contraignant si l'on souhaite mettre en oeuvre des strat'egies d'optimisation plus souples, par exemple, pouvoir changer d'optimiseur en cours d'optimisation, estimer un ou plusieurs m'eta-mod'eles, etc.. . . Nous proposons ici une organisation logicielle selon un paradigme objet o'u les optimiseurs, les simulateurs et les m'eta-mod'eles sont des objets de mˆeme niveau hi'erarchique. L'utilisateur peut alors "jongler" avec ces diff'erents objets pour se contruire des strat'egie d'optimisation personnalis'ees

Fast algorithm for border bases of Artinian Gorenstein algebras

Given a multi-index sequence $$\sigma$$, we present a new efficient algorithm to compute generators of the linear recurrence relations between the terms of $$\sigma$$. We transform this problem into an algebraic one, by identifying multi-index sequences, multivariate formal power series and linear functionals on the ring of multivariate polynomials. In this setting, the recurrence relations are the elements of the kerne l$I$\sigma of the Hankel operator $H$\sigma associated to $$\sigma$$. We describe the correspondence between multi-index sequences with a Hankel operator of finite rank and Artinian Gorenstein Algebras. We show how the algebraic structure of the Artinian Gorenstein algebra $A$\sigma$$associated to the sequence$$\sigma yields the structure of the terms $\sigma\alpha$for all$$\alpha$ $\in$ N n$. This structure is explicitly given by a border basis of$A$\sigma$$, which is presented as a quotient of the polynomial ring$K[x 1 ,. .. , xn$] by the kernel$I$\sigma$$of the Hankel operator$H$\sigma$$. The algorithm provides generators of$I$\sigma$$constituting a border basis, pairwise orthogonal bases of$A$\sigma$$ and the tables of multiplication by the variables in these bases. It is an extension of Berlekamp-Massey-Sakata (BMS) algorithm, with improved complexity bounds. We present applications of the method to different problems such as the decomposition of functions into weighted sums of exponential functions, sparse interpolation, fast decoding of algebraic codes, computing the vanishing ideal of points, and tensor decomposition. Some benchmarks illustrate the practical behavior of the algorithm

Bayesian Identification of Elastic Constants in Multi-Directional Laminate from Moir\'e Interferometry Displacement Fields

The ply elastic constants needed for classical lamination theory analysis of multi-directional laminates may differ from those obtained from unidirectional laminates because of three dimensional effects. In addition, the unidirectional laminates may not be available for testing. In such cases, full-field displacement measurements offer the potential of identifying several material properties simultaneously. For that, it is desirable to create complex displacement fields that are strongly influenced by all the elastic constants. In this work, we explore the potential of using a laminated plate with an open-hole under traction loading to achieve that and identify all four ply elastic constants (E 1, E 2, 12, G 12) at once. However, the accuracy of the identified properties may not be as good as properties measured from individual tests due to the complexity of the experiment, the relative insensitivity of the measured quantities to some of the properties and the various possible sources of uncertainty. It is thus important to quantify the uncertainty (or confidence) with which these properties are identified. Here, Bayesian identification is used for this purpose, because it can readily model all the uncertainties in the analysis and measurements, and because it provides the full coupled probability distribution of the identified material properties. In addition, it offers the potential to combine properties identified based on substantially different experiments. The full-field measurement is obtained by moir\'e interferometry. For computational efficiency the Bayesian approach was applied to a proper orthogonal decomposition (POD) of the displacement fields. The analysis showed that the four orthotropic elastic constants are determined with quite different confidence levels as well as with significant correlation. Comparison with manufacturing specifications showed substantial difference in one constant, and this conclusion agreed with earlier measurement of that constant by a traditional four-point bending test. It is possible that the POD approach did not take full advantage of the copious data provided by the full field measurements, and for that reason that data is provided for others to use (as on line material attached to the article)

The Impact of Shape on the Perception of Euler Diagrams

Euler diagrams are often used for visualizing data collected into sets. However, there is a significant lack of guidance regarding graphical choices for Euler diagram layout. To address this deficiency, this paper asks the question `does the shape of a closed curve affect a user's comprehension of an Euler diagram?' By empirical study, we establish that curve shape does indeed impact on understandability. Our analysis of performance data indicates that circles perform best, followed by squares, with ellipses and rectangles jointly performing worst. We conclude that, where possible, circles should be used to draw effective Euler diagrams. Further, the ability to discriminate curves from zones and the symmetry of the curve shapes is argued to be important. We utilize perceptual theory to explain these results. As a consequence of this research, improved diagram layout decisions can be made for Euler diagrams whether they are manually or automatically drawn

Persuading consumers to reduce their consumption of electricity in the home

Previous work has identified that providing real time feedback or interventions to consumers can persuade consumers to change behaviour and reduce domestic electricity consumption. However, little work has investigated what exactly those feedback mechanisms should be. Most past work is based on an in-home display unit, possibly complemented by lower tariffs and delayed use of non-essential home appliances such as washing machines. In this paper we focus on four methods for real time feedback on domestic energy use, developed to gauge the impact on energy consumption in homes. Their feasibility had been tested using an experimental setup of 24 households collecting minute-by-minute electricity consumption data readings over a period of 18 months. Initial results are mixed, and point to the difficulties of sustaining a reduction in energy consumption, i.e. persuading consumers to change their behaviour. Some of the methods we used exploit small group social dynamics whereby people want to conform to social norms within groups they identify with. It may be that a variety of feedback mechanisms and interventions are needed in order to sustain user interest

Stratification du milieu l'exemple de Ouricuri.

L'introduction d'une inovation technique dans un milieu rural est un element majeur de la demarche recherche-developpement. Elle exige au prealable une bonne connaissance de ce milieu, de ses problemes ainsi qu'un inventaire preci de ses ressources physiques et humaine. Les auteurs, chercheurs du CPATSA (Bresil) presentent une demarche operationnelle qui permet d'identifier dans une zone du Nordeste, malgre l'extreme diversite des situations qui s'y rencontrent, les problemes prioritaires, les acteurs, leur capacite d'action. Face aux problemes essentiels les auteurs confrontent solutions techniques, lieux privilegies d'interventions et public vise. Cette approche est basee sur la stratification du milieu a partir des connaissances physiques acquises par la recherche, validees par la savoirs locaux des gens qui y vivent. Dans chaque cas les solutions proposees prennent en compte le fonctionnement des systemes de production, l'organisation et la strategie des producteurs. Cette demarche peut favoriser la mise au point d'outil de planification d'interventions pour ce developpment

Caracterização do meio físico da margem direito do rio Carinhanha no municipio de Januaria, MG.

Caracteriza o meio fisico da margem direita do rio Carinhanha, abordando a localizacao, a hidrologia, o clima, a geologia, a identificacao do solo (aluviais, quartzosas, hidromorficos e cambissolo), o relevo e a geomorfologia, como tambem o seu aproveitamento.bitstream/item/179527/1/FL-05051.pd

Zoneamento das areas em processo de degradacao ambiental no tropico Semi-Arido do Brasil.

Neste estudo buscou-se aportar uma parcela de conhecimento sobre as areas que se encontram em processo de degradacao ambiental no Nordeste semi-arido, evidenciando uma escala de degradacao que vai desde as areas com baixo nivel de degradacao as areas com nivel severo, com enfase a porcao mais seca, por esta se trata do ambiente mais fragil. Este estudo visa comtribuir com os setores de planejamento nos niveis regional, estadual e municipal, como uma nova forma de planejamento estrategico para regiao. Este estudo fundamenta-se na aplicabilidade do Zoneamento Agroecologico do Nordeste. Trabalho realizado pela EMBRAPA, atraves do CPATSA - Centro de Pesquisa Agropecuaria do Tropico Semi-Arido e da frente de solos Solos Nordeste CNPS.bitstream/item/197281/1/Zoneamento-das-Areas-em-Processo-de-Degradacao-Ambiental-tropico-Semi-Arido-Brasil.pd

Zoneamento agropecuario municipal.

Levantamento dos recursos naturais; Levantamento Socioeconômico.bitstream/item/196679/1/Zoneamento-Agropecuario-Municipal.pd