Estimating the Impact of Highways on Average Travel Velocities and Market Size

In this paper we examine the link between additions to highway infrastructure and development of a market area. We do so by first relating highway travel speeds to added highway-mileage and then relating travel speed to the size of the market area. This approach bypasses issues in the public finance literature that derive from estimates of highway infrastructure spending. Also, rather than examining the effects of improved transportation efficiency on enhancements of productivity, this research examines their effect on enhancements in demand for local production. Our thought, which is borne out in the literature, is that industry-level productivity in a metropolitan area may be improved only marginally by lower delivered prices of inputs due to very localized improvements in the freight transportation system. On the other hand, the market for locally produced goods and services will expand somewhat uniformly across industries due to generally improved traffic movements in a metropolitan area. By applying this approach to data from the Texas Transportation Institute, we find a significant but small positive effect of highways and arterials (as opposed to other roadways) on changes in metropolitan urbanized area and metropolitan population change. This suggests that demand for local production may well be enhanced by expansions of highway and principal arterials infrastructure.

Extracting quasi-steady Lagrangian transport patterns from the ocean circulation: An application to the Gulf of Mexico

We construct a climatology of Lagrangian coherent structures (LCSs), the concealed skeleton that shapes transport, with a twelve-year-long data-assimilative simulation of the sea-surface circulation in the Gulf of Mexico (GoM). Computed as time-mean Cauchy-Green strain tensorlines of the climatological velocity, the climatological LCSs (cLCSs) unveil recurrent Lagrangian circulation patterns. cLCSs strongly constrain the ensemble-mean Lagrangian circulation of the instantaneous model velocity, thus we show that a climatological velocity may preserve meaningful transport information. Also, the climatological transport patterns we report agree well with GoM kinematics and dynamics, as described in several previous observational and numerical studies. For example, cLCSs identify regions of persistent isolation, and suggest that coastal regions previously identified as high-risk for pollution impact, are regions of maximal attraction. Also, we show examples where cLCSs are remarkably similar to transport patterns observed during the Deepwater Horizon and Ixtoc oil spills, and during the Grand LAgrangian Deployment (GLAD) experiment. Thus, it is shown that cLCSs are an efficient way of synthesizing vast amounts of Lagrangian information. The cLCS method confirms previous GoM studies, and contributes to our understanding by revealing the persistent nature of the dynamics and kinematics treated therein.Comment: To be submitte

Morbidade psiquiátrica em crianças com alterações neurológicas

Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PsiquiatriaInstitute of Psychiatry at the Maudsley Child and Adolescent Psychiatry DepartmentUNIFESP, EPM, Depto. de PsiquiatriaSciEL

Programación del Fixture de la Segunda División del Fútbol de Chile mediante Investigación de Operaciones

Presentamos en este trabajo la aplicación de técnicas de Investigación de Operaciones a la programación del fixture de la Segunda División del fútbol de Chile. Este fixture debe cumplir una serie de condiciones solicitadas por la Asociación Nacional de Fútbol Profesional (ANFP), entidad que organiza el torneo. El criterio geográfico es particularmente importante, debido a que la disposición de algunos equipos en lugares extremos del país implica largos desplazamientos, a menudo realizados por vía terrestre. Abordamos el problema mediante un modelo de programación lineal entera que define cuándo y dónde se juega cada partido del torneo, sujeto a que todas las condiciones se cumplen. Para las instancias más difíciles, desarrollamos un modelo adicional también de programación lineal entera que genera patrones de localías y los asigna a los equipos, previo a la ejecución del modelo que define la programación de los partidos. Los fixtures así generados han sido exitosamente utilizados en los cinco torneos de Segunda División que se han disputado entre 2007 y 2010, reemplazando la metodología aleatoria que la ANFP utilizaba anteriormente. Durante este período, el tipo de torneo ha sufrido diversas modificaciones, incluyendo un cuádruple round-robin y un torneo en dos etapas que considera fases regionales y nacionales. Hemos debido entonces adaptar nuestros modelos temporada tras temporada, según el tipo de torneo. Esta aplicación marca un nuevo avance en el uso de Investigación de Operaciones para la gestión del fútbol chileno, que se suma a otros proyectos desarrollados en la misma línea en los últimos años.Fil: Duran, Guillermo Alfredo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guajardo, Mario. Norwegian School of Economics and Business Administration; NoruegaFil: Wolf Yadlin, Rodrigo. Universidad de Chile; Chil

Las clausulas abusivas en los contratos por adhesion

73 p.El contrato por adhesión es una buena fuente de estudio debido a las particularidades que posee y que lo diferencian de la noción clásica de contrato. La principal diferenciación es la forma en que una de las partes expresa su voluntad, esto es, por medio de la adhesión. Hasta hace poco la doctrina no se ponía de acuerdo en determinar su naturaleza jurídica, así algunos autores señalaban que la adhesión no constituía voluntad o era insuficiente para generar un contrato, mientras que otros sostenían que la adhesión es una forma de manifestación de la voluntad del adherente que genera el contrato por adhesión. Pero la naturaleza jurídica no es el único tema a discutir. Un tema importante y de gran utilidad práctica son las cláusulas abusivas que puede contener este contrato, ya que al omitirse la negociación es el oferente quien distribuye los derechos y las cargas, lo que le otorga una cierta peligrosidad al permitir la introducción de cláusulas abusivas. Hasta el año 1997 el marco normativo de las cláusulas abusivas era escaso, se limitaba a la teoría general del contrato, a la breve ley 18.223 y a algunos decretos supremos que indirectamente le eran aplicables. Fue en ese año que se dictó la ley 19.496 que establece normas especiales que regulan las cláusulas abusivas en este contrato, sin embargo, estas normas no son suficiente ya que escapan de ella múltiples supuestos no sancionados. Teniendo presente que ningún legislador puede prever todos los casos, puesto que algunos son impredecibles, una buena solución es establecer una cláusula abierta que pudiera integrar aquellos que escapan de la enumeración legal. Este trabajo tiene como objetivo establecer el marco normativo que otorga nuestra legislación a las cláusulas abusivas en los contratos por adhesión. Para el estudio del tema se tuvo en cuenta tres fuentes: la ley 19.496, los principios generales del derecho como la buena fe, el orden público y las buenas costumbres; y el derecho comparado. Quizás si hubiera existido una jurisprudencia abundante se podría haber agregado el criterio aplicado por nuestros tribunales para el control de cláusulas abusivas en los contratos por adhesión, sin embargo, es casi inexistente

Operations research techniques for scheduling chile's second division soccer league

In this paper, we use operations research (OR) techniques to schedule the Second Division of the Chilean professional soccer league. The solution must satisfy a series of conditions requested by league officials. Because the teams generally travel long distances by bus, geographical restrictions are particularly important. We specify the scheduling problem and solve it using an integer linear programming (ILP) model that defines when and where each match is played, subject to constraints. For the most difficult instances, we formulate a second ILP model that generates home-away patterns and assigns them to the teams; we then run the model, which determines the match schedule. Chilean league officials have successfully used the models to schedule all five Second Division tournaments between 2007 and 2010, replacing the random scheduling methodology that they used previously. Since 2007, the two formulations have been adapted to various formats with which the Second Division has experimented; these include a quadruple round robin and a two-phase tournament with zonal and national phases. The application we present is one of a number of such projects that the authors and their colleagues developed over the past few years, and it represents an expansion of the use of OR techniques for managing tasks in Chilean soccer.Fil: Duran, Guillermo Alfredo. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Guajardo, Mario. NHH Norwegian School of Economics; NoruegaFil: Wolf Yadlin, Rodrigo. Universidad de Chile; Chil

Establishing suitability of an ocean model for a poleward undercurrent study

Modifications of an ocean model are described, as the objective for which the model was used changed to study the kinematics and dynamics of an eastern-boundary poleward undercurrent

Kinematics and Dynamics of a Model Eastern-boundary Poleward Undercurrent

A carefully calibrated primitive-equation model from 41°N to 48°N is used to study the poleward undercurrent off the US west coast. Chapter 2 describes poleward flow over the slope from Eulerian and Lagrangian perspectives. The model is robust, in the sense of several characteristics being qualitatively consistent with observational and modeling studies. For example, poleward flow reaches the surface at the right times, and is an undercurrent at the right times and in the right locations, the cross-shelf scale is 25km. The robust representation also points to qualities that do not conform to the typical way we think of undercurrents. None the less, it is very likely that the reader would find in observational studies (provided they measure deep enough) that poleward flow over the slope persists year round, albeit deeper than about 400m in spring, that poleward flow over the slope typically reaches 1–1.5 km deep, and that poleward flow tends to reach the surface during upwelling months, except when and where there is a coastal jet; numerical models tend to be qualitatively consistent with this representation. A variety of references in the discussion of chapter 2 support this description. This work benefitted from analyzing a relatively small domain and short (one year) simulation, allowing attention to be paid to the details that resulted in a somewhat unusual description, despite supporting evidence spanning 6 decades of scientific literature. Chapter 2 also gives a definition of the undercurrent using Eulerian and Lagrangian information, and is used in chapter 3 to study the dynamics. Additional descriptions of the model coastal flow, for example cross-shelf and vertical connectivity, may be of interest to researchers studying hypoxia, fisheries or upwelling-related productivity. Chapter 3 investigates model-undercurrent dynamics by analyzing momentum and vorticity balances. First order momentum balances are as expected: decisively geostrophic in the zonal equation, and geostrophic with ageostrophic contributions in the meridional equation. In the second order two-dimensional balance, the zonal equation is mainly a balance between the ageostrophic pressure gradient (pressure gradient minus Coriolis acceleration), except during upwelling when zonal wind is negligible and advection takes its place. Through the year, the meridional equation is mainly a balance between the ageostrophic pressure gradient and meridional wind. Bottom stress increases in importance during upwelling months. The three-dimensional vorticity balance does not explain the undercurrent because there is a term that is proportional to the undercurrent (identical in vertical and cross-shelf structure) yet it is an order of magnitude smaller than the leading balance; the signal of interest is buried in noise. Vorticity from the depth-integrated balance supports this result: topographic waves and an advective signal are considerably more energetic than the undercurrent signal of interest. Vorticity from both the depth-averaged and depth-integrated momentum equations reveal that the main balance is an arrested topographic wave with an additional term, advection of planetary vorticity; equivalently, the main balance is topographic Sverdup with an additional contribution from Ekman pumping due to bottom stresses. Evidence is presented to advance the hypothesis that the main undercurrent balance is the arrested topographic wave, as suggested by Pedlosky and Csanady in the 1970’s and 1980’s, with a small barotropic contribution (<10%) due to Sverdrup balance. This dynamical explanation is consistent with the description of poleward flow reaching the surface during upwelling months, except when and where there is an upwelling coastal jet. Each of chapters 2 and 3, is a standalone manuscript, from abstract through discussion

Predicting the most likely state for a basic geophysical flow : theoretical framework

Statistical mechanics studies the probability that a system is in a certain state given one or more constraints which are usually fixed conserved quantities. It is a particularly useful and powerful approach for problems with a large number of degrees of freedom where a complete knowledge of the system is not practical or even possible. By allowing to reduce the complexity of the system to a few parameters, statistical mechanics allows avoiding the question of 'what is the state of a system?' by asking instead 'what is the most likely state of the system given some known constraints?'. Holloway (1986) has a review of successful applications of statistical mechanics to a variety of geophysical fluid dynamics (GFD) problems, including geostrophic turbulence over topography, two-dimensional turbulence on a plane and on a sphere, closed-basin circulation and Western intensification, the shape of a thermocline, baroclinic turbulence, eddy heat transport, predictability (i.e. sensitivity of flow evolution to perturbations in the initial conditions), stirring of tracer fields, internal gravity waves and buoyant turbulence among others. More recently, statistical mechanics has been successfully used to understand aspects of large-scale GFD. For example the Robert-Sommeria-Miller (RSM) equilibrium statistical mechanics has been used to interpret rings and jets as statistical equilibria (Bouchet & Venaille 2012). Statistical Mechanics has also been successfully applied to numerical GFD, a subject of great interest for humanity not only for purely scientific reasons, but also for the large number of applications to real life. A sharp increase in the ability to numerically simulate oceans and atmospheres, as well as in the interest of projecting current states into the future have fueled important developments in numerical GFD. The rest of this paper is organized into a section 2 where the equations of geophysical fluid dynamics and some simplifications are introduced; some details of the simplified equations like non-linear stability of the steady state solution are also presented. Section 3 develops the theory of statistichal mechanics. We obtain a probability function with which we can predict the most-likely state of the system describing a generalized flow. In section 4 we predict the most likely state of a basic geophysical flow. The first step applies the theory of section 3 to a Galerkin approximation of the simplified equations from section 2. The final step extends the result to a continuum by taking the limit to infinity of the truncated system. An appendix includes material for some of the concepts we use