116 resultados para galaxies: cluster: general
Resumo:
Les infraestructures de recerca inclouen diferent tipologies, des d’instal·lacions úniques a altres basades en xarxes. Típicament han sorgit de necessitats específiques d’una disciplina o bé multidisciplinàries. Les infraestructures de recerca produeixen, processen o gestionen volums heterogenis d’informació, tant grans com petits. Són les anomenades “fàbriques de dades científiques” del segle XXI. Comprenen diversos tipus de recursos d’informació com publicacions, col·leccions digitalitzades, objectes d’aprenentatge i dades de recerca. Les qüestions clau d'avui dia per a les infraestructures de recerca són el seu coneixement per part dels investigadors, i la seva viabilitat, sostenibilitat i interoperabilitat. El compromís de les biblioteques de recerca amb les infraestructures de recerca ha estat baix. Si bé això podria ser comprensible el 2005, quan les primeres prioritats per les inversions en infraestructures de recerca s’estaven definint, ara representa un gran buit en l'estratègia europea. Iniciatives clau com ESFRI no inclouen cap participació per part de biblioteques de recerca, amb excepció de DARIAH. La participació en projectes finançats per la Unió Europea (a través de LIBER o directament a través d'institucions) es va centrar (amb algunes excepcions) en les àrees de digitalització, patrimoni cultural i publicacions. Les biblioteques de recerca han d'esdevenir actors visibles en les discussions estratègiques sobre les infraestructures de recerca i haurien d’explorar activament la seva participació en les infraestructures de dades d'investigació. Accés Obert, Ciència Oberta (dades), les dades de recerca (infraestructures i gestió) són els catalitzadors per aconseguir que les biblioteques de recerca siguin presents pels investigadors més enllà de les humanitats i les ciències socials. "L'accés obert és global - però la seva aplicació és local '. Aquest és popular lema del projecte OpenAIRE i dóna a les biblioteques de recerca locals un paper important en el context europeu. Les dades de recerca són específiques segons les disciplines, però les polítiques, els fluxos de treball i les normes també s'han d'aplicar a nivell local. La creació d'infraestructures participatives amb la participació d’actors institucionals, nacionals i temàtics ha estat identificat per la Unió Europea com una tasca clau per a la dècada actual. El terme 'participatiu' també es considera d'importància fonamental per a l'estratègia de la política europea, ja que s'adapta molt bé amb la coordinació a nivell nacional i europeu per aconseguir una eficiència de costos i contribueix a evitar la duplicació de treball. Els principals desafiaments per a la construcció d'un ecosistema coherent, finançable i sostenible no es troben en les TIC, sinó més aviat en la gestió, la normativa, l'organització, els aspectes socioculturals, la confiança, i, per descomptat, els costos.
Resumo:
An alternative approach to the fundamental general physics concepts has been proposed. We demonstrate that the electrostatic potential energy of a discrete or a continuous system of charges should be stored by the charges and not the field. It is found that there is a possibility that any electric field has no energy density, as well as magnetic field. It is found that there is no direct relation between the electric or magnetic energy and photons. An alternative derivation of the blackbody radiation formula is proposed. It is also found that the zero-point of energy of electromagnetic radiation may not exist.
Resumo:
We developed a procedure that combines three complementary computational methodologies to improve the theoretical description of the electronic structure of nickel oxide. The starting point is a Car-Parrinello molecular dynamics simulation to incorporate vibrorotational degrees of freedom into the material model. By means ofcomplete active space self-consistent field second-order perturbation theory (CASPT2) calculations on embedded clusters extracted from the resulting trajectory, we describe localized spectroscopic phenomena on NiO with an efficient treatment of electron correlation. The inclusion of thermal motion into the theoretical description allowsus to study electronic transitions that, otherwise, would be dipole forbidden in the ideal structure and results in a natural reproduction of the band broadening. Moreover, we improved the embedded cluster model by incorporating self-consistently at the complete active space self-consistent field (CASSCF) level a discrete (or direct) reaction field (DRF) in the cluster surroundings. The DRF approach offers an efficient treatment ofelectric response effects of the crystalline embedding to the electronic transitions localized in the cluster. We offer accurate theoretical estimates of the absorption spectrum and the density of states around the Fermi level of NiO, and a comprehensive explanation of the source of the broadening and the relaxation of the charge transferstates due to the adaptation of the environment
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S'ha creat un entorn web que permet executar les tasques d'administració que comporta un cluster, de firma gràfica. Algunes d'aquestes tasques són la creació de còpies seguretat o la gestió d'usuaris i grups. A més, des d'aquest entorn es permet la monitorització del cluster, per veure els seus recursos i l'estat dels nodes.
Resumo:
Dissenyar i implementar un planificador en l'espai d'usuari basant-se en la tècnica de coscheduling, en concret s'utilitzarà coscheduling predictive. L'objectiu és intentar obtenir un rendiment similar al que es va assolir en implementacions de la mateixa tècnica realitzada en l'espai de kernel.
Resumo:
Selected configuration interaction (SCI) for atomic and molecular electronic structure calculations is reformulated in a general framework encompassing all CI methods. The linked cluster expansion is used as an intermediate device to approximate CI coefficients BK of disconnected configurations (those that can be expressed as products of combinations of singly and doubly excited ones) in terms of CI coefficients of lower-excited configurations where each K is a linear combination of configuration-state-functions (CSFs) over all degenerate elements of K. Disconnected configurations up to sextuply excited ones are selected by Brown's energy formula, ΔEK=(E-HKK)BK2/(1-BK2), with BK determined from coefficients of singly and doubly excited configurations. The truncation energy error from disconnected configurations, Δdis, is approximated by the sum of ΔEKS of all discarded Ks. The remaining (connected) configurations are selected by thresholds based on natural orbital concepts. Given a model CI space M, a usual upper bound ES is computed by CI in a selected space S, and EM=E S+ΔEdis+δE, where δE is a residual error which can be calculated by well-defined sensitivity analyses. An SCI calculation on Ne ground state featuring 1077 orbitals is presented. Convergence to within near spectroscopic accuracy (0.5 cm-1) is achieved in a model space M of 1.4× 109 CSFs (1.1 × 1012 determinants) containing up to quadruply excited CSFs. Accurate energy contributions of quintuples and sextuples in a model space of 6.5 × 1012 CSFs are obtained. The impact of SCI on various orbital methods is discussed. Since ΔEdis can readily be calculated for very large basis sets without the need of a CI calculation, it can be used to estimate the orbital basis incompleteness error. A method for precise and efficient evaluation of ES is taken up in a companion paper
Resumo:
Background: To enhance our understanding of complex biological systems like diseases we need to put all of the available data into context and use this to detect relations, pattern and rules which allow predictive hypotheses to be defined. Life science has become a data rich science with information about the behaviour of millions of entities like genes, chemical compounds, diseases, cell types and organs, which are organised in many different databases and/or spread throughout the literature. Existing knowledge such as genotype - phenotype relations or signal transduction pathways must be semantically integrated and dynamically organised into structured networks that are connected with clinical and experimental data. Different approaches to this challenge exist but so far none has proven entirely satisfactory. Results: To address this challenge we previously developed a generic knowledge management framework, BioXM™, which allows the dynamic, graphic generation of domain specific knowledge representation models based on specific objects and their relations supporting annotations and ontologies. Here we demonstrate the utility of BioXM for knowledge management in systems biology as part of the EU FP6 BioBridge project on translational approaches to chronic diseases. From clinical and experimental data, text-mining results and public databases we generate a chronic obstructive pulmonary disease (COPD) knowledge base and demonstrate its use by mining specific molecular networks together with integrated clinical and experimental data. Conclusions: We generate the first semantically integrated COPD specific public knowledge base and find that for the integration of clinical and experimental data with pre-existing knowledge the configuration based set-up enabled by BioXM reduced implementation time and effort for the knowledge base compared to similar systems implemented as classical software development projects. The knowledgebase enables the retrieval of sub-networks including protein-protein interaction, pathway, gene - disease and gene - compound data which are used for subsequent data analysis, modelling and simulation. Pre-structured queries and reports enhance usability; establishing their use in everyday clinical settings requires further simplification with a browser based interface which is currently under development.
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La nostra comunicació s'emmarca en la Catalunya deIs inicis del regnat de Felip II (III de Castella). Té per objecte la complexa situació que es produeix quan, amb motiu d'una convocatoria de Corts, la Diputació del General es troba frec a frec amb els tres braços als quals està legalment subordinada. La convivència forçada d'ambdues institucions en el mateix quadre polític, ni que sigui durant lapses de temps relativament curts, esdevé cada cop més problematica a mesura que avança el segle XVI.
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Aquesta obra estudia els juraments pronunciats pels reis, pels oficials municipals i pels oficials reials en el municipi de Barcelona des del segle XIII fins el Decret de Nova Planta.
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Tots hem sentit a parlar del canvi del Raval en aquests últims anys. Actualment la majoria del jovent no només hi estudia sinó que hi passa la major part del seu tempsd’oci, en bars, restaurants, museus, galeries d’art, comerços...Nosaltres ens hem preguntat: Per què el Raval ha canviat tant? S’han fet molts treballs, molts estudis, s’han intentat trobar les diverses causes que han produït aquest fenòmen.Més específicament ens hem preguntat: Pot ser que degut a la construcció del cluster cultural format pel MACBA i el CCCB, entre d’altres, s’hagi produït aquest canvi?Així doncs, en aquest treball intentarem contestar ambdues preguntes. Intentarem ser precisos, concisos, breus i clars; esperem que us resulti interessant.
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In this paper, we develop a general equilibrium model of crime and show thatlaw enforcement has different roles depending on the equilibrium characterization and the value of social norms. When an economy has a unique stable equilibrium where a fraction of the population is productive and the remaining predates, the government can choose an optimal law enforcement policy to maximize a welfare function evaluated at the steady state. If such steady state is not unique, law enforcement is still relevant but in a completely different way because the steady state that prevails depends on the initial proportions of productive and predator individuals in the economy. The relative importance of these proportions can be changed through law enforcement policy.
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This work presents an application of the multilevel analysis techniques tothe study of the abstention in the 2000 Spanish general election. Theinterest of the study is both, substantive and methodological. From thesubstantive point of view the article intends to explain the causes ofabstention and analyze the impact of associationism on it. From themethodological point of view it is intended to analyze the interaction betweenindividual and context with a modelisation that takes into account thehierarchical structure of data. The multilevel study of this paper validatesthe one level results obtained in previous analysis of the abstention andshows that only a fraction of the differences in abstention are explained bythe individual characteristics of the electors. Another important fraction ofthese differences is due to the political and social characteristics of thecontext. Relating to associationism, the data suggest that individualparticipation in associations decrease the probability of abstention. However,better indicators are needed in order to catch more properly the effect ofassociationism in electoral behaviour.
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Our work attempts to investigate the influence of credit tightness orexpansion on activity and relative prices in a multimarket set-up. We report on somedouble- auction, two-market experiments where subjects had to satisfy an inequalityinvolving the use of credit. The experiments display two regimes, characterizedby high and low credit availability. The critical value of credit at the commonboundary of the two regimes has a compelling interpretation as the maximal credituse at the Arrow-Debreu equilibrium of the abstract economy naturally associatedto our experimental environment. Our main results are that changes in theavailability of credit: (a): have minor and unsystematic effects on quantitiesand relative prices in the high-credit regime, (b): have substantial effects, bothon quantities and relative prices, in the low-credit regime.