Search results for "programming"
showing 10 items of 3090 documents
Population dynamics based on ladder bosonic operators
2021
Abstract We adopt an operatorial method, based on truncated bosons, to describe the dynamics of populations in a closed region with a non trivial topology. The main operator that includes the various mechanisms and interactions between the populations is the Hamiltonian, constructed with the density and transport operators. The whole evolution is derived from the Schrodinger equation, and the densities of the populations are retrieved from the normalized expected values of the density operators. We show that this approach is suitable for applications in very large domain, solving the computational issues that typically occur when using an Hamiltonian based on fermionic ladder operators.
A Sample of Field Ellipticals
2003
Using well-defined selection criteria applied to the LEDA galaxy catalogue we have constructed a sample of elliptical galaxies that can be taken to lie in the field. Such criteria can easily be applied to theoretical simulations for direct comparison with observations. The variation of the number of `isolated' ellipticals with selection criteria is also investigated. A preliminary study of the environment of the field ellipticals shows that, in the mean, they are surrounded by a population of dwarf galaxies, out to projected radii of at least 500 kpc, with a radial density profile of $r^{-0.6\pm 0.2}$ and a luminosity function slope of $\alpha \sim -1.8$. The results are compared and contra…
Shape design optimization in 2D aerodynamics using Genetic Algorithms on parallel computers
1996
Publisher Summary This chapter presents two Shape Optimization problems for two dimensional airfoil designs. The first one is a reconstruction problem for an airfoil when the velocity of the flow is known on the surface of airfoil. The second problem is to minimize the shock drag of an airfoil at transonic regime. The flow is modeled by the full potential equations. The discretization of the state equation is done using the finite element method and the resulting non-linear system of equations is solved by using a multi-grid method. The non-linear minimization process corresponding to the shape optimization problems are solved by a parallel implementation of a genetic algorithm (GA). Some n…
Automated astrographic plates measuring process
1990
The astrographic plates measuring process applied at the Astronomical Observatory of Valencia has been described.
Data quality monitors of vertex detectors at the start of the Belle II experiment
2019
The Belle II experiment features a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider at KEK in Tsukuba, Japan. The accelerator completed its first phase of commissioning in 2016, and the Belle II detector saw its first electron-positron collisions in April 2018. Belle II features a newly designed silicon vertex detector based on double-sided strip layers and DEPFET pixel layers. A subset of the vertex detector was operated in 2018 to determine background conditions (Phase 2 operation). The collaboration completed full detector installation in January 2019, and the experiment started full data taking. This paper will report on the fin…
Market for ideas and reception of physiocracy in Spain: some analytical and historical suggestions
1995
This essay aims to situate the phenomenon of the international spread of the economic ideas of a particular school of thought within the framework of the ‘market for ideas' approach outlined by George Stigler. On the one hand, the paper attempts to amplify the theoretical model of a demand-driven market for ideas, introducing the concepts of public goods, utility, transaction costs and other institutional variables, and on the other this analytical approach is applied to the Spanish market for ideas of the 18th century and its reception of physiocracy, obtaining a new perspective on the spread of ideas of the iconomistes in comparison with the existing literature.
There is no clam with coats in the calm coast: delimiting the transposed-letter priming effect.
2009
In this article, we explore the transposed-letter priming effect (e.g., jugde–JUDGE vs. jupte–JUDGE), a phenomenon that taps into some key issues on how the brain encodes letter positions and has favoured the creation of new input coding schemes. However, almost all the empirical evidence from transposed-letter priming experiments comes from nonword primes (e.g., jugde–JUDGE). Indeed, previous evidence when using word–word pairs (e.g., causal–CASUAL) is not conclusive. Here, we conducted five masked priming lexical decision experiments that examined the relationship between pairs of real words that differed only in the transposition of two of their letters (e.g., CASUAL vs. CAUSAL). Result…
Schuchardt, Hugo (1842–1927)
2006
H. Schuchardt's doctoral thesis submitted to Bonn University in 1862 became the basis of the famous three volumes on the vocalism of Vulgar Latin (1866–1868), building a bridge between Classical and Romance Philology. He became a full professor of Romance Philology in Halle, Central Germany, and thereafter in Graz, Austria (1876–1900). In his 770 publications, Schuchardt dealt with the classification of Romance dialects, with etymologies and the cultural background of words discussed, and with descriptions of Portuguese-, French-, Spanish-, English- and Dutch-based creole languages so that Schuchardt became the founder of creolistics. Language mixture in Europe, Africa and Asia was describe…
On the Conceptual History of the Term Lingua Franca
2015
This paper aims to give an outline of the development of the term “Lingua Franca”. Initially the proper name of an extinct pidgin, to “Lingua Franca”, the term has become a common noun, used with regard to language contact phenomena in general – at first specifically for pidgins and trade languages, but now for all vehicular languages. This broader usage is especially prominent in the field of research known as “English as a lingua franca” (ELF). Using ELF as an example, it is shown that the modern usage is partly inconsistent and can be misleading, as it connects a positive feature of the original Lingua Franca, viz linguistic equality, with a language with native speakers like English, wh…
A Study on the Measurement Instrumentation for a Custom-Made Bipendulum Impact Testing Machine
2008
Experimental investigations of structures under impact loads are normally carried out by means of drop-weight testing rigs, which are often tailor made, and require sensors for fast transient measurement of mechanical quantities (namely, force, displacement, velocity, and absorbed energy). Since these tests are quite expensive, time consuming, and, often, not repeatable, the sensors must provide reliable and interpretable results in the first trial. In this paper, a thorough study on the measurement instrumentation suitable to carry out reliable low-velocity impact tests by means of a custom-made bipendulum impact testing machine is presented. Attention has been focused on the choice of the…