Estimating the integral length scale on turbulent flows from the zero crossings of the longitudinal velocity fluctuation

The integral length scale ($\mathcal{L}$) is considered to be characteristic of the largest motions of a turbulent flow, and as such, it is an input parameter in modern and classical approaches of turbulence theory and numerical simulations. Its experimental estimation, however, could be difficult in certain conditions, for instance, when the experimental calibration required to measure $\mathcal{L}$ is hard to achieve (hot-wire anemometry on large scale wind-tunnels, and field measurements), or in 'standard' facilities using active grids due to the behaviour of their velocity autocorrelation function $\rho(r)$, which does not in general cross zero. In this work, we provide two alternative methods to estimate $\mathcal{L}$ using the variance of the distance between successive zero crossings of the streamwise velocity fluctuations, thereby reducing the uncertainty of estimating $\mathcal{L}$ under similar experimental conditions. These methods are applicable to variety of situations such as active grids flows, field measurements, and large scale wind tunnels

ON THE PERFORMANCE OF NONPARAMETRIC SPECIFICATION TESTS IN REGRESSION MODELS

Some recently developed nonparametric specification tests for regression models are described in a unified way. The common characteristic of these tests is that they are consistent against any alternative hypothesis. The performance of the test statistics is compared by means of Monte Carlo simulations, analysing how heteroskedasticity, number of regressors and bandwidth selection influence the results. The statistics which do not use a bandwidth perform slightly better if the regression model has only one regressor; otherwise, some of the statistics which use a bandwidth behave better if the bandwidth is chosen adequately. These statistics are applied to test the specification of three commonly used Mincer-type wage equations with Uruguayan and Spanish data; all of them are rejected.

Diseño de un plan de gestión de costo y de tiempo para la administración de proyectos de la empresa constructora Jiménez y Sojo

Proyecto de Graduación (Licenciatura en Ingeniería en Construcción) Instituto Tecnológico de Costa Rica. Escuela de Ingeniería en Construcción, 2010.This project is based on the design of a management plan that includes cost and time for the project administration of the construction company Jiménez & Sojo, company responsible for applying the present project. It is expected to design and implement the best methodology for the subject under discussion, the project management. To achieve this, it was necessary to use the Guide for the Fundamentals of Project Management. Based on it, it was necessary to develop also the range of projects. To accomplish this goal, it was decided to propose a methodology for the three areas in discussion, range, cost and time, using templates and interrelated tools that allow their development. As a final product, it was necessary to develop a manual of procedures in order to initiate, plan and monitor more closely the construction projects that will be developed in the company. It´s concluded that the generation of the above management plan allows companies to develop future construction projects more effectively and with more order in their administration. This is why the referred proposed plan should be viewed as a tool to execute construction projects in a standardized manner to reduce the downside risks and increase the quality and productivity.Instituto Tecnológico de Costa Rica. Escuela Ingeniería en Construcción; Empresa constructora Jiménez y Sojo

Human resource allocation to multiple projects based on members’ expertise, group heterogeneity and social cohesion

Project managers regularly allocate human resources to construction projects. This critical task is usually executed by fulfilling the minimum project staffing requirements normally based around the quantity and competence of project members. However, research has shown that team performance can increase by up to 10% and 18%, respectively, as a consequence of the group members’ heterogeneity and social cohesion. Also, there is currently no practical quantitative tool which incorporates these aspects to allow project managers to achieve this task efficiently and objectively. A new quantitative model for the effective allocation of human resources to multiple projects, which takes into account group heterogeneity and social cohesion is proposed. This model is easy to build, update and use in real project environments with the use of a spreadsheet and a basic optimization engine (e.g. Excel Solver). A case study is proposed and solved with a Genetic Algorithm to illustrate the model implementation. Finally, a validation example is provided to exemplify how group heterogeneity and social cohesion condition academic achievement in an academic setting

La reestructuración de un sector industrial para el progreso económico de la capital

Artículo de gradoEste artículo expone el desarrollo propuesto en el sector zona industrial conllevando a los primeros acercamientos al problema, el cual determina ¿Cómo a través de la reestructuración de un sector con dos usos dominantes se mitigan las problemáticas que estas generan? Por lo cual la propuesta urbana interviene directamente en la conformación de una distribución equilibrada de estos usos, e incorporando a su vez espacios que potencialicen la calidad de vida y de trabajo para la población del sector.Introducción Metodología 1. Resultados 2. Reestructuración A Supermanzanas 3. Centro De Innovación E Investigación Industrial 4. Discusion 5. Conclusiones Referencias Tabla De Figuras AnexosPregradoArquitect

Real-time near replica detection over massive streams of shared photos

Aquest treball es basa en la detecció en temps real de repliques d'imatges en entorns distribuïts a partir de la indexació de vectors de característiques locals

Computing decomposable multigroup indices of segregation

Existen ocho índices de segregación multigrupo que son descomponibles en dos partes que miden la segregación que pueda haber 1) "entre" y 2) "dentro" de ciertas grupos o unidades. Estos ocho índices consisten en dos versiones de 1) el índice de información mutua, 2) el índice simétrico de Atkinson, 3) el índice de diversidad relativa y 4) el índice H de Theil. En este artículo, presentamos el comando dseg, con el que calcular todos. Contribuye al conjunto de comandos de segregación en Stata al 1) realizar la descomposición, 2) proporcionar los pesos e índices locales utilizados en el cálculo del término "dentro", 3) facilitar la implementación de las propiedades de descomposición de los ocho índices en escenarios complejos que requieren soluciones personalizadas, y 4) complementar los datos muestrales con pruebas de bootstrap y aleatorización aproximada. Ilustramos el uso de dseg analizando datos del censo de 2017 de las escuelas públicas de los Estados Unidos para medir la segregación racial en estas. Los principales resultados son: (1) la mayor parte de la segregación racial en las escuelas no se debe a estas en sí sino a la segregación racial entre estados y distritos. (2) Sólo alrededor de la mitad de la segregación escolar se debe a la separación entre estudiantes blancos y estudiantes de minorías raciales; la otra mitad se origina entre las distintas minorías (asiáticos, hispanos, negros, etc.).We also acknowledge the financial support of Spain’s Ministry of Science (MCIN/AEI/10.13039/501100011033, project number PID2019-108576RB-I00)

Publishing Linked Data - There is no One-Size-Fits-All Formula

Publishing Linked Data is a process that involves several design decisions and technologies. Although some initial guidelines have been already provided by Linked Data publishers, these are still far from covering all the steps that are necessary (from data source selection to publication) or giving enough details about all these steps, technologies, intermediate products, etc. Furthermore, given the variety of data sources from which Linked Data can be generated, we believe that it is possible to have a single and uni�ed method for publishing Linked Data, but we should rely on di�erent techniques, technologies and tools for particular datasets of a given domain. In this paper we present a general method for publishing Linked Data and the application of the method to cover di�erent sources from di�erent domains