Recapturas de Chorlitejo Patinegro (Charadrius alexandriunus) en una localidad costera de Odesa (Ucrania)

S'han constatat diferències entre localitats pel que fa a la fidelitat del corriol camanegre al lloc de cria. En aquest treball s'analitza aquest paràmetre a una regió d'Ucraïna. Durant 1985 es van anellar un total de 248 ocells a Odessa, dels quals 24 (9,6%) es van recapturar posteriorment el 1986. Tres d'aquests ocells havien estat anellats com a polls. El 12% dels corriols foren recapturats al mateix lloc on s'havien anellat inicialment. Això suggereix una certa fidelitat interanual d'aquesta espècie no només a una mateixa zona, sinó també al mateix indret on havien nidificat prèviament

Ejecución de la construcción del reforzamiento del edificio del centro comercial Plaza Wong

Proyecto de Graduación (Licenciatura en Ingeniería en Construcción) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería en Construcción, 2016.This final graduation project entitled "Implementation of the construction of the reinforcement of the building of the Plaza Wong shopping center" is an informative document about the construction process necessary to carry out the reinforcement, both columns and foundations, of a work not only unfinished But defective. The objective of this professional practice is the coordination, execution and supervision of the reinforcement of the building. From the review of the initial state of the construction it is clear that four global activities are required: excavation of columns, foundation, and reinforcement of columns and elaboration of subfloor. This required a daily field inspection, as well as gathering information on the materials and equipment of each task. Control of the cost and duration of the activities was carried out, as well as to identify the risks and how to mitigate them. All in order that the final implementation result fully complies with the new structural design, which does comply with the requirements of the Costa Rican seismic code and soil conditions As a result, a detailed description of the building reinforcement process is shown. The reinforcement lasted 115 days and a total cost of 80.027.488 colones, including materials, machinery and labor. The resulting cost is not the least possible. In addition to several drawbacks during the activities, other factors such as a late soil study affect the final cost. It is for this reason that the documentation of the contingencies and their solutions are of great help to future constructions that require a process similar to the one described in this document.Centro Comercial Plaza Won

Unified formulation of a family of iterative solvers for power systems analysis

This paper illustrates the construction of a new class of iterative solvers for power flow calculations based on the method of Alternating Search Directions. This method is fit to the particular algebraic structure of the power flow problem resulting from the combination of a globally linear set of equations and nonlinear local relations imposed by power conversion devices, such as loads and generators. The choice of the search directions is shown to be crucial for improving the overall robustness of the solver. A noteworthy advantage is that constant search directions yield stationary methods that, in contrast with Newton or Quasi-Newton methods, do not require the evaluation of the Jacobian matrix. Such directions can be elected to enforce the convergence to the high voltage operative solution. The method is explained through an intuitive example illustrating how the proposed generalized formulation is able to include other nonlinear solvers that are classically used for power flow analysis, thus offering a unified view on the topic. Numerical experiments are performed on publicly available benchmarks for large distribution and transmission systems.Peer ReviewedPostprint (author's final draft

Theoretical and experimental structural studies of historical Latin-American laminated planked timber arches

This article describes a first group of theoretical and experimental works undertaken at the Polytechnic University of Madrid. One major purpose is to obtain a structural model for the assessment of historical Latin-American vertically laminated planked timber arches built by the Spanish, mainly in the XVII and XVIII centuries. Many of those constructions still stand and represent a notable historical heritage. Pedro Hurtado recently presented his Ph. D. thesis on historical and construction topics. A structural study was then undertaken. This step of the structural research focussed on static analysis, most especially the deformation in the connection system. This article describes part of this first structural research. Even though it is still at a basic level, it shows reasonable agreement with the experimental results. Further static analytical models are been now developed and implemented. The next stage will address the dynamic problem, even though improvements will be made also in the constitutive equations

Homological Region Adjacency Tree for a 3D Binary Digital Image via HSF Model

Given a 3D binary digital image I, we define and compute an edge-weighted tree, called Homological Region Tree (or Hom-Tree, for short). It coincides, as unweighted graph, with the classical Region Adjacency Tree of black 6-connected components (CCs) and white 26- connected components of I. In addition, we define the weight of an edge (R, S) as the number of tunnels that the CCs R and S “share”. The Hom-Tree structure is still an isotopic invariant of I. Thus, it provides information about how the different homology groups interact between them, while preserving the duality of black and white CCs. An experimentation with a set of synthetic images showing different shapes and different complexity of connected component nesting is performed for numerically validating the method.Ministerio de Economía y Competitividad MTM2016-81030-

Las elecciones al Ayuntamiento vitoriano durante la Restauración

El trabajo analiza el desarrollo de las elecciones en Vitoria-Gasteiz desde fines del S.XIX hasta la segunda década del S.XX. Expone las relaciones de fuerzas políticas locales (los candidatos) y los diferentes resultados electorales de los distritos, así como una valoración de los resultados y de las incidencias que de ellos deriva

Characterizing the Temperature of SAT Formulas

The remarkable advances in SAT solving achieved in the last years have allowed to use this technology to solve many real-world applications, such as planning, formal verification and cryptography, among others. Interestingly, these industrial SAT problems are commonly believed to be easier than classical random SAT formulas, but estimating their actual hardness is still a very challenging question, which in some cases even requires to solve them. In this context, realistic pseudo-industrial random SAT generators have emerged with the aim of reproducing the main features of these application problems to better understand the success of those SAT solving techniques on them. In this work, we present a model to estimate the temperature of real-world SAT instances. This temperature represents the degree of distortion into the expected structure of the formula, from highly structured benchmarks (more similar to real-world SAT instances) to the complete absence of structure (observed in the classical random SAT model). Our solution is based on the popularity–similarity random model for SAT, which has been recently presented to reproduce two crucial features of application SAT benchmarks: scale-free and community structures. This model is able to control the hardness of the generated formula by introducing some randomizations in the expected structure. Using our regression model, we observe that the estimated temperature of the applications benchmarks used in the last SAT Competitions correlates to their hardness in most of the cases.Juan de la Cierva program, fellowship IJC2019-040489-I, funded by MCIN and AE