1000 resultados para Wheel-rail interaction
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This file contains the results of application of the model (4.6) and (4.8)
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Guidance document detailing the suggested process for the critical friend team interaction
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Abstract In this talk, I'll focus on the work we've been doing on evaluating the cognitive side of dealing with information resources and increasingly complex user interfaces. While we can build increasingly powerful user interfaces, they often come at the cost of simple design and ease of use. I'll describe two specific studies: 1) work on the ORCHID project focused on measuring mental workload during tasks using fNIRS (a blood-oxygen-based brain scanner), and 2) a evaluation metric for measuring how much people learn during tasks. Together these provide advances towards understanding the cognitive side of information interaction, in working towards building better tools for users.
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In Metropolitan Area of Mexico City, most of urban displacements happen through semi formal public transportation: small and medium capacity vehicles operated by small private enterprises, through a concession scheme. This kind of public transportation has been playing a major role in the Mexican capital. On one hand, it has been one of the conditions for urbanization to be possible. On the other hand, despite its uncountable deficiencies, public transportation has allowed for a long time the whole population to be able to move within this huge metropolis. However, that important function with regards to integration has now reached its limits in the most recent suburbs of the city, where a new mode of urbanization is taking place, based on massive production of very big social housing gated settlements. Public transportation tends to constitute here a factor of exclusion and households meet with important difficulties for their daily mobility.
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La operación de mega minería que abarca CERREJON se desarrolla bajo lo más altos estándares de seguridad y calidad, con el compromiso de entregar al mercado un excelente producto y evitando el deterioro del entorno. Uno de los puntos más fuertes de la compañía se haya en la integración de los procesos productivos entre la mina de carbón, el ferrocarril y el puerto, logrando que la operación sea eficiente y que garantice niveles altos de óptimos resultados y que los porcentajes de falla no existan o cada vez sean menores en el proceso de explotación y transporte del carbón de Colombia hacia el mundo. El departamento de MATERIALES es el punto de origen para garantizar que se desarrolle la operación, dado que el departamento tiene la gran labor de adquirir y entregar los bienes y servicios requeridos por la Compañía al más bajo costo total evaluado, en el menor tiempo posible y bajo el marco de la legislación Colombiana en el proceso de nacionalización, con un alto énfasis en el desarrollo de relaciones fuertes y sinérgicas entre todos los eslabones de la cadena. Todo el proceso del departamento se enmarca dentro de un ciclo que debe encaminarse a ser cada vez más efectivo y eficiente; de allí que se busquen opciones de mejoramiento para afinar los procesos. Para que sea posible y factible manejar una mega operación como esta se requiere afinar al máximo la red que se establece en su cadena de abastecimiento, buscando lograr un flujo de producto, información y fondos que garanticen disponibilidad del producto, para así generar una rentabilidad alta a la compañía, y controlar los costos por la operación. Dado que la cadena de suministro es susceptible a mejoras, gracias a la interacción con los proveedores, colaboradores y clientes; se pretende sacar el mejor provecho de esto, a través del análisis de la cadena actual de CERREJON; presentando una opción de mejora en uno de los eslabones del proceso productivo, esta opción ha sido contemplada desde años anteriores, pero en esta ocasión gracias a la integración de afinamientos en los sistemas de información, y la participación activa de los proveedores, se encuentra una opción viable de la eliminación de un reproceso, que garantiza eficiencia y efectividad en la agilización del ciclo de producción en CERREJON. A través de la ejecución del proyecto de reforma del conteo, se presenta la oportunidad de mejoramiento en la cadena del departamento; el proceso de reconteo en la mina, realizado posteriormente al conteo inicial en Puerto Bolívar, de los materiales que llegan importados vía marítima. El proceso de afinamiento del recibo documental en el consolidador de carga y los mayores proveedores de entrega directa (HITACHI y MCA) al transportador, genera la opción del uso de terminales portátiles, que de la mano con los ajustes documentales, permitirán que la carga sea contada y separada por localización, para enviarla vía tren a LMN, reduciendo tiempo de entrega al cliente final, los costos de remanejo al volver a contar, y los costos asociados a las entregas no oportunas de devolución de contenedores.
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We look at at the empirical validity of Schelling’s models for racial residential segregation applied to the case of Chicago. Most of the empirical literature has focused exclusively the single neighborhood model, also known as the tipping point model and neglected a multineighborhood approach or a unified approach. The multi-neighborhood approach introduced spatial interaction across the neighborhoods, in particular we look at spatial interaction across neighborhoods sharing a border. An initial exploration of the data indicates that spatial contiguity might be relevant to properly analyse the so call tipping phenomena of predominately non-Hispanic white neighborhoods to predominantly minority neighborhoods within a decade. We introduce an econometric model that combines an approach to estimate tipping point using threshold effects and a spatial autoregressive model. The estimation results from the model disputes the existence of a tipping point, that is a discontinuous change in the rate of growth of the non-Hispanic white population due to a small increase in the minority share of the neighborhood. In addition we find that racial distance between the neighborhood of interest and it surrounding neighborhoods has an important effect on the dynamics of racial segregation in Chicago.
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Resumen basado en el de la publicación. Resumen en español
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Esta publicación anima a los estudiantes a mirar más allá de las estrategias convencionales de comunicación y practicar el lenguaje hablado en diferentes contextos. Ofrece más de cien actividades para que los estudiantes vean el idioma inglés a través de diálogos y puedan hablar de literatura, los medios de comunicación, así como extractos de una conversación auténtica. Tiene índice y bibligrafía.
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Resumen tomado de la publicaci??n
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Monogr??fico con el t??tulo: " Formaci??n de profesores. Perspectivas de Brasil, Colombia, Espa??a y Portugal"
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Selected configuration interaction (SCI) for atomic and molecular electronic structure calculations is reformulated in a general framework encompassing all CI methods. The linked cluster expansion is used as an intermediate device to approximate CI coefficients BK of disconnected configurations (those that can be expressed as products of combinations of singly and doubly excited ones) in terms of CI coefficients of lower-excited configurations where each K is a linear combination of configuration-state-functions (CSFs) over all degenerate elements of K. Disconnected configurations up to sextuply excited ones are selected by Brown's energy formula, ΔEK=(E-HKK)BK2/(1-BK2), with BK determined from coefficients of singly and doubly excited configurations. The truncation energy error from disconnected configurations, Δdis, is approximated by the sum of ΔEKS of all discarded Ks. The remaining (connected) configurations are selected by thresholds based on natural orbital concepts. Given a model CI space M, a usual upper bound ES is computed by CI in a selected space S, and EM=E S+ΔEdis+δE, where δE is a residual error which can be calculated by well-defined sensitivity analyses. An SCI calculation on Ne ground state featuring 1077 orbitals is presented. Convergence to within near spectroscopic accuracy (0.5 cm-1) is achieved in a model space M of 1.4× 109 CSFs (1.1 × 1012 determinants) containing up to quadruply excited CSFs. Accurate energy contributions of quintuples and sextuples in a model space of 6.5 × 1012 CSFs are obtained. The impact of SCI on various orbital methods is discussed. Since ΔEdis can readily be calculated for very large basis sets without the need of a CI calculation, it can be used to estimate the orbital basis incompleteness error. A method for precise and efficient evaluation of ES is taken up in a companion paper
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A select-divide-and-conquer variational method to approximate configuration interaction (CI) is presented. Given an orthonormal set made up of occupied orbitals (Hartree-Fock or similar) and suitable correlation orbitals (natural or localized orbitals), a large N-electron target space S is split into subspaces S0,S1,S2,...,SR. S0, of dimension d0, contains all configurations K with attributes (energy contributions, etc.) above thresholds T0={T0egy, T0etc.}; the CI coefficients in S0 remain always free to vary. S1 accommodates KS with attributes above T1≤T0. An eigenproblem of dimension d0+d1 for S0+S 1 is solved first, after which the last d1 rows and columns are contracted into a single row and column, thus freezing the last d1 CI coefficients hereinafter. The process is repeated with successive Sj(j≥2) chosen so that corresponding CI matrices fit random access memory (RAM). Davidson's eigensolver is used R times. The final energy eigenvalue (lowest or excited one) is always above the corresponding exact eigenvalue in S. Threshold values {Tj;j=0, 1, 2,...,R} regulate accuracy; for large-dimensional S, high accuracy requires S 0+S1 to be solved outside RAM. From there on, however, usually a few Davidson iterations in RAM are needed for each step, so that Hamiltonian matrix-element evaluation becomes rate determining. One μhartree accuracy is achieved for an eigenproblem of order 24 × 106, involving 1.2 × 1012 nonzero matrix elements, and 8.4×109 Slater determinants
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Linear response functions are implemented for a vibrational configuration interaction state allowing accurate analytical calculations of pure vibrational contributions to dynamical polarizabilities. Sample calculations are presented for the pure vibrational contributions to the polarizabilities of water and formaldehyde. We discuss the convergence of the results with respect to various details of the vibrational wave function description as well as the potential and property surfaces. We also analyze the frequency dependence of the linear response function and the effect of accounting phenomenologically for the finite lifetime of the excited vibrational states. Finally, we compare the analytical response approach to a sum-over-states approach
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L'objectiu d'aquest estudi és el d'investigar sobre l'ús de matèria orgànica per part dels fongs i bacteris que colonitzen diferents substrats bentònics en rius Mediterranis i analitzar l'efecte dels factors ambientals i antròpics sobre l'estabilitat estructural i funcional de les comunitats del biofilm. La metodologia emprada en aquest estudi consisteix en: i) anàlisi de la biomassa bacteriana i fúngica, ii) anàlisi de la composició de les comunitats bentòniques (identificació d'hifomicets aquàtics i anàlisi del 16S rDNA bacterià), i iii) anàlisi de l'activitat enzimàtica extracel·lular relacionada amb el reciclatge de matèria orgànica en rius.
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This paper discusses an ongoing project that aims at improving the potential for resilience of a system responsible for the planning of rail engineering work delivery. It focuses on the use of a human factors based approach as a way to achieve this end. In particular, the paper discusses the initial data collected by means of interviews and how this process gave way to a two fold goal: Understanding how the planning process works in reality and identifying any critical aspects of the system from a Resilience Engineering perspective. Given the nature of the process under study, information flows and communication issues have been given particular attention throughout the data collection and analysis stages. Initial data confirms that the planning process is greatly reliant on the capability of people using their knowledge and skills to communicate in a dynamic informational environment. Finally, the added value of the interviews is discussed from a human factors perspective and as a mean towards the aim of better understanding resilience in rail engineering planning.