On the optimal level of public inputs.

This paper studies the optimal level of public inputs under two different tax settings. With this aim, we adapt the approach by Gronberg and Liu (2001) to the case of productivity-enhancing public spending. We find that it is not analytically clear whether the first-best level of public spending exceeds the second-best level. After taking account the type of public input, a wide numerical simulation has been carried out. We obtain that the second-best level is always below the first-best level but the criterion by Gronberg and Liu has to be qualified.Second best, excess burden, public input.

Optimization in non-standard problems. An application to the provision of public inputs

This paper describes a new method for solving non-standard constrained optimization problems for which standard methodologies do not work properly. Our method (the Rational Iterative Multisection -RIM- algorithm) consists of different stages that can be interpreted as different requirements of precision by obtaining the optimal solution. We have performed an application of RIM method to the case of public inputs provision. We prove that the RIM approach and comparable standard methodologies achieve the same results with regular optimization problems while the RIM algorithm takes advantage over them when facing non-standard optimization problems.direct search, constrained optimization, multisection, optimal taxation, public input.

How sensitive is the provision of public inputs to specifications?

This paper studies the sensitivity of provision of public inputs to changes in the specification of technology and consumer preferences. We consider a simple model in which the government, with recourse to three different tax settings (a lump-sum tax, a tax on labour and a tax on economic profit), provides firms with certain productive services. We focus on the numerical results coming from the government optimization problem. We look at several specific cases in which the returns to scale in the production function emerges as a critical issue. Our …findings also address the impact of changes in output elasticity, in consumer preferences and in the number of households on the levels of public input and utility.firm-augmenting public input, factor-augmenting public input, optimal provision

Incidencia del programa ambiental de gestión de riesgo de desastre y cambio climático MARENA-PAGRICC en el primer ciclo, en el municipio de san isidro, departamento de Matagalpa, micro cuenca Las Mangas, comunidades de Llano del Boquerón y Mal Paso

El programa Ambiental de Gestión de Riesgos y Cambio Climático (PAGRICC) ejecutado por MARENA pretende en su momento reducir la vulnerabilidad de los protagonistas en la Micro cuenca las Mangas y las comunidades de estudio Llano del Boquerón y Mal Paso, por lo tanto la investigación evaluó la incidencia del programa ambiental en su primer ciclo en el municipio de San Isidro Departamento de Matagalpa en el segundo semestre del año 2014, el propósito de la investigación fue conocer el proceso de identificación y selección de los beneficiarios, realizados en las comunidades y de ésta manera valorar las trasformaciones que los protagonistas que han alcanzado en el desarrollo de los sistemas de restauración ambiental (SRA) practicados en sus comunidades. De ésta manera se puede identificar el grado de ejecución del programa ambiental (PAGRICC) para alcanzar los objetivos esperados por el programa; en el estudio realizado se valoraron las transformaciones sociales, económicas y ambientales desde los protagonistas, concluyendo que la ejecución del programa fue de suma importancia para enfrentar los fenómenos climatológicos que afectan al Municipio de San Isidro de igual manera la reducción de la vulnerabilidad de la zona ante la sequía, lo cual el estudio del programa contribuyó a los indicadores en las mejoras del ingreso, producción y desempleo. En el cumplimiento y desarrollo del programa según el reglamento operativo del este mismo se determina que las transformaciones ayudaron al mejoramiento de las condiciones de los protagonistas y de igual manera a sus fincas o parcelas; así de esta manera se les propone tanto a los protagonistas del programa, como a las diferentes entidades participantes la mejora en las debilidades encontradas en el estudio de camp

Mixing in convective thermal fluxes in unsteady nonhomogeneous flows generating complex three dimensional vorticity patterns

Diffusion and scaling of the velocity and vorticity in a thermoelectric driven heating and cooling experimental device is presented in order to map the different patterns and transitions between two and three dimensional convection in an enclosure with complex driven flows. The size of the water tank is of 0.2 x 0.2 x 0.1 m and the heat sources or sinks can be regulated both in power and sign [1-3]. The thermal convective driven flows are generated by means of Peltier effects in 4 wall extended positions of 0.05 x 0.05 cm each. The parameter range of convective cell array varies strongly with the Topology of the boundary conditions. Side heat and momentum fluxes are a function of Rayleigh, Peclet and Nusselt numbers, [4-6] Visualizations are performed by PIV, Particle tracking and shadowgraph. The structure of the flow is shown by setting up a convective flow generated by buoyant heat fluxes. The experiments described here investigate high Prandtl number mixing using brine and fresh water in order to form a density interface and low Prandtl number mixing with temperature gradients. The evolution of the mixing fronts are compared and the topological characteristics of the merging of the convective structures are examined for different configurations. Based on two dimensional Vorticity spectral analysis, new techniques can be very useful to determine the evolution of scales considering the multi-fractal structure of the convective flows.Peer ReviewedPostprint (published version

Project-based learning experience on Data Structures course

This paper presents the innovations in the practical work of the Data Structures subject carried out in the last five years, including a transition period and a first year of implantation of the European Higher Education Area. The practical coursework is inspired by a project-based methodology and from 2008/2009 additional laboratory sessions are included in the subject schedule. We will present the academic results and ratios of the mentioned time period which imply a significant improvement on students' performance

An Improved Phase Filter for Differential SAR Interferometry Based on an Iterative Method

Phase quality is a key element in the analysis of the deformation of the Earth's surface carried out with differential synthetic aperture radar interferometry. Various decorrelation sources may degrade the surface deformation estimates, and thus, phase filters are needed for this kind of application. The well-known Goldstein filter is the most widely used due to its simple implementation and computational efficiency. In the past years, improved filters have been proposed, which are based on this filter but introduce variations in the data processing. The effectiveness of these filters mostly depends on the size of the filtering window, the weight of the smoothed spectrum, and the kernel used to filter the spectrum. In this paper, we evaluate the performance of four of these filters and present a new method that outperforms all of them. The proposed filter is based on an iterative method in which the original phase is denoised progressively with adaptive filtering windows of different sizes. The effectiveness of the filter is controlled by the interferometric coherence, a direct indicator of the phase quality. Moreover, we introduce some modifications regarding the processing of the power spectrum. Specifically, we propose to smooth the original phase using a new filter which is based on a Chebyshev interpolation scheme. The performance of the new filter has been tested on both simulated and real interferograms, acquired by RADARSAT-2 and the Uninhabited Aerial Vehicle Synthetic Aperture Radar, which mapped two different geological events that caused surface deformation.This work was supported in part by the Spanish Ministry of Economy, Industry and Competitiveness, in part by the State Agency of Research (AEI), in part by the European Funds for Regional Development under Project TIN2014-55413-C2-2-P and Project TEC2017-85244-C2-1-P, in part by the U.K. Natural Environmental Research Council through the Looking Inside the Continents under Grant NE/K011006/1, in part by the Rapid deployment of a seismic array in Ecuador following the April 16th 2016 M7.8 Pedernales earthquake under Grant NE/P008828/1, and in part by the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics under Grant COMET, GA/13/M/031

Propuesta de implementación de un sistema de gestión de seguridad y salud en el trabajo en base a la ley N° 29783 de una empresa de servicios de operación de minas

En la actualidad uno de los desafíos a la que debe afrontar las empresas Mineras, quienes deben administrar en forma científica – prospectiva la prevención de incidentes e accidentes, con relación a los programas existentes. Para que el presente trabajo de investigación nos Asegure el desarrollo de una cultura preventiva de seguridad y salud fomentando el liderazgo compromiso y participación en cada uno de los miembros, promoviendo el conocimiento y fácil entendimiento de los estándares procedimientos y prácticas para realizar trabajos bien hechos. Los beneficios que resultan de este tipo de gestión van a permitir un aumento en la autoestima y orgullo del personal debido al reconocimiento de sus esfuerzos y asegura un desarrollo efectivo y eficiente eliminando en lo posible las perdidas. El minimizar la perdida es tan provechoso como maximizar las utilidades. Por ello el presente trabajo de investigación tiene por objetivo determinar medidas con la finalidad de llega al cumplimiento eficiente de las normas de orden técnico legal y social cuyo fin supremo es la protección de la vida humana, la salud y la seguridad

Development and Implementation of a Direct Evaluation Solution for Fault Tree Analyses Competing With Traditional Minimal Cut Sets Methods

Fault tree analysis (FTA) is a well-established technique to analyze the safety risks of a system. Two specific prominent FTA methods, largely applied in the aerospace field, are the so-called minimal cut sets (MCS), which uses an approximate evaluation of the problem, and the direct evaluation (DE) of the fault tree, which uses a top-down recursive algorithm. The first approach is only valid for small values of basic event probabilities and has historically yielded faster results than exact solutions for complex fault trees. The second one means exact solutions at a higher computational cost. This article presents several improvements applied to both approaches in order to upgrade the computing performance. First, improvements to the MCS approach have been performed, where the main idea has been to optimize the number of required permutations and to take advantage of the available information from previous solved subsets. Second, improvements to the DE approach have been applied, which deal with a reduction of the number of recursive calls through a deep search for independent events in the fault tree. This could dramatically reduce the computation time for industrial fault trees with a high number of repeated events. Additional implementation improvements have been also applied regarding hash tables, and memory access and usage, but also implementing the so-called “virtual gates”, which enable limitless children on each gate. The results presented hereafter are promising, not only because they show that both approaches have been highly optimized compared to the literature, but also because a DE solution has been achieved, which can compete in time resources (and obviously in precision) with the MCS approach. These improvements are relevant when considering the industrial, and more specifically the aeronautical, implementation and application of both techniques.The author Jordi Pons‐Prats acknowledges the support from Serra Hunter programme, Generalitat de Catalunya, as well as the support through the Severo Ochoa Centre of Excellence (2019‐2023) under the grant CEX2018‐000797‐S funded by MCIN/AEI/10.13039/501100011033.Postprint (author's final draft

Estimation of effective diffusion coefficient and its effect on effectiveness factor for hds catalytic process: a multi-scale approach

Effectiveness factors have great relevance in multiphase reactors modeling since they are the conventional way of incorporating the effects of intra-particle resistance reaction rate. This work determines the description level effect of catalytic pellet microstructure on mass and energy effective transport coefficients prediction, isothermal and no isothermal. For such a purpose some results about on evaluation of the effective diffusivity and conductivity with the methodology of volume averaging were applied. The obtained results along with a Langmuir–Hinshelwood/Hougen–Watson kinetic expression were applied to establish the concentration and temperature fields in a catalytic particle. The evaluation of concentration field and effectiveness factors were developed using two different models: pseudohomogeneous mass and energy transport model for a catalytic particle with reaction in all domain, and heterogeneous mass and energy transport model with fluid-catalytic surface interphase reaction for a realistic porous structure model. The results show the differences in concentration and temperature profiles between both models and consequently in effectiveness factors. This could be ascribed to the form of evaluation of effective transport coefficients used in the pseudo-homogeneous model, and presumably to the simple shape of the unit cells used for the solution of the closure problem for the average transport equations with homogeneous reaction