Commuting Time and Labour Supply: A Causal Effect?

We analyze the causal effect of the length of the worker’s commute on worker's productivity, by examining whether commuting time has any effect on worker's labour market supply. Using the Spanish Time Use Survey 2002-03, our GMM/IV estimation yields a positive causal impact of commuting time on the time devoted to the labour market, with one hour of commuting increasing the time devoted to the labour market by 35 minutes in a working day. Our results shed light on the relationship between commuting and workers behaviour, since daily labour supply should be considered in theoretical models to provide a comprehensive view of commuter behaviour.commuting, labour supply, productivity, causality, Time Use Survey

Semivalues: power,potential and multilinear extensions

The notions of power and potential, both defined for any semivalue, give rise to two endomorphisms of the vector space of all cooperative games on a given player set. Several properties of these linear mappings are stated and their action on unanimity games is emphasized. We also relate in both cases the multilinear extension of the image game to the multilinear extension of the original game.Cooperative game; Semivalue; Power; Potential; Multilinear extension

A concept of weighted connectivity on connected graphs

The introduction of a {0,1}-valued game associated to a connected graph allows us to assign to each node a value of weighted connectivity to the different solutions that for the cooperative games are obtained by means of the semivalues. The marginal contributions of each node to the coalitions differentiate an active connectivity from another reactive connectivity, according to whether the node is essential to obtain the connection or it is the obstacle for the connection between the nodes in the coalition. Diverse properties of this concept of connectivity can be derived.Peer ReviewedPostprint (author’s final draft

Separability by semivalues modified for games with coalition structure

The original publication is available at www.rairo-ro.orgTwo games are inseparable by semivalues if both games obtain the same allocation whatever semivalue is considered. The problem of separability by semivalues reduces to separability from the null game. For four or more players, the vector subspace of games inseparable from the null game by semivalues contains games different to zero-game. Now, for five or more players, the consideration of a priori coalition blocks in the player set allows us to reduce in a significant way the dimension of the vector subspace of games inseparable from the null game. For these subspaces we provide basis formed by games of a particular type.Postprint (published version

Earnings and Wealth Inequality and Income Taxation: Quantifying the Trade-Offs of Switching to a Proportional Income Tax in the U.S. Ohio

This papaer quantifies the steady-state aggregate, distributinal and mobility effects of switching the U.S. to a proportional income tax system. As a perriquisite to the analysi, we propose a theory of earnings and wealth inequality capable of accounting quantitatively for the key aggregate and inequality facts of the U. S. economy. This theory is based on saving to smooth uninsured household-specific risk, for dynastic households that also have some life-cycle characteristics. A suitable calibration of our model economy replicates the U.S. growth facts, earnings and wealth distributions, the progressivity of the tax system and the size of the U.S. government. We also solve a similar model economy in which the government livies a proportional income tax to finance the same flow of government expenditures and public transfers. Our finding show that in this class of model worlds a switch from the U.S. tax system to a proporcional tax system implies the following trade-offs, i.) it increases efficiency as measured by aggregate output by 4,4%, ii. ) it increases inequality as measured by the Gini index of the wealth distribution by 10.4%, and iv.) it changes by little the mobility between the different earnings and wealth groups

Unemployment spells and income distribution dynamics

In the U.S., during the 1948-86 period, an approximation to the Gini Index based on the quintiles and on the top 5% of the income distribution yielded a value of 0.351. Further, during this same period, the income share earned by the first quintile was procyclical and 7% more volatile than aggregate yearly output. In this paper we quantify the role played by unemployment spells in determining these and other related issues. To this purpose, we use an extension of the general equilibrium stochastic growth model that includes an endogenous distribution of households indexed by wealth and employment status. Our main findings are the following: i) in a model economy where all households have the same endowments of skills and are subject to the same employment processes, uninsured unemployment spells alone account for a very small share of the concentration of income observed in the U.S., and of the income distribution dynamics -the approximated Gini Index in this model economy is 18% of the one observed in the U.S., and the income share earned by the first quintile is 58% more volatile, ii) this result is robust to including a technology that allows for cyclically moving factor shares, and iii) in a model economy where households are partitioned into different skills groups that are subject to different employment processes in accordance to U.S. data, unemployment spells account for a significantly greater share of the U.S. statistics -the approximated Gini Index in this model economy is 70% of the one observed in the U.S., and the income share earned by the first quintile is 10% more volatile

Synthesis of the Complete Inverse Kinematic Model of Non-Redundant Open-Chain Robotic Systems using Groebner Basis Theory

[ES] Uno de los elementos más importantes en el sistema de control de un robot es su Modelo Cinemático Inverso (IKM, por sus siglas en inglés), el cual calcula las referencias de posición y velocidad requeridas para que dicho robot pueda seguir una trayectoria. Los métodos más comúnmente empleados para la síntesis del IKM de sistemas robotizados de cadena cinemática abierta dependen fuertemente de la geometría del robot, por lo que no son procedimientos sistemáticos que puedan ser aplicados uniformemente en todas las situaciones. Este proyecto presenta el desarrollo de un procedimiento sistemático para la síntesis del IKM completo de sistemas robotizados no redundantes de cadena cinemática abierta usando la teoría de Bases de Groebner, el cual no depende de la geometría del robot. Las entradas del procedimiento desarrollado son los parámetros de Denavit-Hartenberg del robot y el rango de movimiento de sus actuadores, mientras que la salida es el IKM sintetizado, listo para ser usado en el sistema de control del robot o en una simulación de su funcionamiento. El desempeño del procedimiento desarrollado fue demostrado sintetizando los IKMs de un manipulador PUMA y un hexápodo caminante. Los tiempos de ejecución de ambos IKMs son comparables con los requeridos por los modelos cinemáticos calculados por procedimientos tradicionales, y los errores de las referencias que ofrecen como salida son totalmente despreciables. Los IKMs sintetizados son completos, porque no sólo ofrecen las referencias de posición para todos los actuadores del robot, sino que también calculan las correspondientes referencias de velocidades y aceleraciones de dichos actuadores, por lo que el procedimiento desarrollado puede ser empleado en una amplia variedad de sistemas robotizados.[CA] Un dels elements més importants en el sistema de control d'un robot és el seu Model Cinemàtic Invers (IKM, per les seues sigles en anglés), el qual calcula les referències de posició i velocitat requerides perquè aquest robot puga seguir una trajectòria. Els mètodes més comunament emprats per a la síntesi del IKM de sistemes robotitzats de cadena cinemàtica oberta depenen fortament de la geometria del robot analitzat, per la qual cosa no són procediments sistemàtics que puguen ser aplicats uniformement en totes les situacions. Aquest projecte presenta el desenvolupament d'un procediment sistemàtic per a la síntesi del IKM complet de sistemes robotitzats no redundants de cadena cinemàtica oberta usant la teoria de Bases de Groebner, el qual no depén de la geometria del robot. Les entrades del procediment desenvolupat són els paràmetres de Denavit-Hartenberg del robot i el rang de moviment dels seus actuadors, mentre que l'eixida és el IKM sintetitzat, llest per a ser usat en el sistema de control del robot o en una simulació del seu funcionament. L'acompliment del procediment desenvolupat va ser demostrat sintetitzant els IKMs d'un manipulador PUMA i un robot caminante. Els temps d'execució de tots dos IKMs són comparables amb els requerits pels models cinemàtics calculats per procediments tradicionals, i els errors de les referències que ofereixen com a eixida són totalment menyspreables. Els IKMs sintetitzats són complets, perquè no sols ofereixen les referències de posició per a tots els actuadors del robot, sinó que també calculen les corresponents referències de velocitats i acceleracions d'aquests actuadors, per la qual cosa el procediment desenvolupat pot ser emprat en una àmplia varietat de sistemes robotitzats.[EN] One of the most important elements of a robot's control system is its Inverse Kinematic Model (IKM), which calculates the position and velocity references required by the robot's actuators to follow a trajectory. The methods that are commonly used to synthesize the IKM of open-chain robotic systems strongly depend on the geometry of the analyzed robot, so they are not systematic procedures that can be applied equally in all situations. This project presents the development of a systematic procedure to synthesize the complete IKM of non-redundant open-chain robotic systems using Groebner Basis theory, which does not depend on the robot's geometry. The inputs to the developed procedure are the robot's Denavit-Hartenberg parameters and the movement range of its actuators, while the output is the IKM, ready to be used in the robot's control system or in a simulation of its behavior. This procedure's performance was proved synthesizing the IKMs of a PUMA manipulator and a walking hexapod robot. The computation times of both IKMs are comparable to those required by the kinematic models calculated by traditional methods, while the errors of their computed references were absolutely negligible. The synthesized IKMs are complete in the sense that they not only supply the position reference for all the robot's actuators, but also the corresponding references for their velocities and accelerations, so the developed procedure can be used in a wide range of robotic systems.Guzmán Giménez, J. (2022). Synthesis of the Complete Inverse Kinematic Model of Non-Redundant Open-Chain Robotic Systems using Groebner Basis Theory [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181632TESI

Reform and change of Martinon Factory use

Reform and change of use of a building located in the Raval neighborhood of Barcelona. The main objective is to carry out a large reform of the entire building to change its current use, but without losing its substance, because it has a great historical story. In this reform, each floor will be used for a different use. The ground floor will be a restaurant, the first floor a party room and the second floor will offer enough space for offices all of them connected with the vertical communicative stairway. This is one of the main elements of the building which will be preserved certainly also in combination with the necessary implementation of a new modern elevator, since currently the forklift does not comply with regulations. Furthermore I will analyse the current situation of the building (materials used, construction techniques and energy certificate), with the target of preserving the building structure largely and implementing some new usages. For this reason another main objective will be the renewal of all installations for gas, water, sanitary and electricity. As result of the project I will present a 3D visualization (3Ds max) which will offer a very realistic overview of the interior design of the different rooms.Reforma y cambio de uso de edificio situado en el barrio del Raval de Barcelona. El objetivo principal es realizar una reforma integral de todo el edificio para cambiar su uso actual, pero sin llegar a perder su esencia, ya que tiene un gran recorrido histórico. En esta reforma cada planta estará destinada a diferentes usos, dónde la planta baja será un restaurante, la primera planta sala de fiestas y la segunda planta oficinas, accediendo a cada una de ellas a través de la escalera de comunicación vertical, que es uno de los principales elementos singulares que conserva el edificio, y la nueva instalación de un elevador neumático adaptado para minusválidos, ya que actualmente el montacargas no cumple normativa. A parte analizaré el estado actual en el que se encuentra el edificio (materiales utilizados, técnicas constructivas y certificado energético), con el objetivo de conservar la mayor parte de estructura y de mejorar algunos aspectos como las instalaciones, por este motivo otro de mis objetivos es realizar toda la instalación nueva de fontanería, saneamiento, electricidad y gas. Para finalizar el proyecto, quiero representar y visualizar en 3D (3Ds max) las distintas estancias haciéndolo lo más realista posible, dándole mucha importancia al ámbito de interiorismo

Estrés en estudiantes de enfermería durante sus prácticas clínicas en unidad de hospitalización a domicilio

Por medio de este estudio deseamos conocer las situaciones que generan estrés entre las/os estudiantes de enfermería durante sus prácticas hospitalarias, en una Unidad de Hospitalización a Domicilio (UHD), y como estos factores estresantes se relacionan con variables sociodemográficas y laborales. Se elaboró un estudio transversal, descriptivo – comparativo y correlacional, planteado a 15 estudiantes de enfermería, utilizando el cuestionario KEZKAK modificado, como instrumento de medida. Los datos recogidos fueron analizados estadísticamente con el programa OpenStat 11.9.08 y se valoró las asociaciones con un grado de significación de p<0,05. Como resultado se obtuvo que las/os estudiantes presentan altos niveles de estrés durante sus prácticas clínicas. Y los estresores más importantes son los relacionados con el desconocimiento, impotencia e incertidumbre que les genera una situación clínica real. Como conclusión, las mujeres tenían niveles más altos de estrés que los hombres, en relación con las situaciones emocionales. En los hombres, el nivel de estrés se asocia más a los episodios clínicos no controlados. Y para reducir estos niveles de estrés las/os estudiantes de enfermería solicitan la implantación de programas de prevención del estrés