Handover en LTE basado en distancia en plataforma de simulación

[ES]Mejorar el proceso de handover en el despliegue de comunicaciones inalámbricas de banda ancha tradicionalmente ha motivado muchas iniciativas de investigación. En el dominio de los ferrocarriles de alta velocidad, el reto es incluso mayor. Debido a las largas distancias que se cubren, el nodo móvil se ve envuelto en una secuencia obligatoria de procesos de handover. Consecuentemente, un rendimiento pobre en la ejecución de esos procesos de handover degrada significativamente el rendimiento global extremo a extremo. Este documento propone una nueva estrategia de handover para el dominio de los ferrocarriles: un algoritmo de decisión para LTE basado en distancia en lugar de en potencia. La decisión de realizar el handover se realiza cuando un eNB candidato se encuentra más cerca del UE que el eNB fuente. Adicionalmente, cabe la posibilidad de retrasar esa decisión mediante un umbral. Asimismo, se añade una nueva función al modelo de LTE de la plataforma de simulación empleada en la verificación de este modelo. Este mecanismo de decisión introduce un retardo menor en los procesos de handover y, en consecuencia, la calidad extremo-a-extremo aumenta.

A study of the proposed Santa Fe extension from the present Redondo Branch at El Segundo to Los Angeles Harbor

The Los Angeles Harbor at San Pedro with its natural advantages, and the big development of these now underway, will very soon be the key to the traffic routes of Southern California. The Atchison, Topeka, and Santa Fe railway company realizing this and, not wishing to be caught asleep, has planned to build a line from El Segundo to the harbor. The developments of the harbor are not the only developments taking place in these localities and the proposed new line is intended to include these also.

A comparison of the costs of operation of the motor bus, Birney safety car, and trolley bus on the local transportation routes in Pasadena

With the installation by the Pacific Electric Railway of a bus system in Pasadena to supplant most of its trolley lines, the problem of the comparison of the costs of the two systems naturally presented itself. The study here undertaken was originally started as just a comparison of the motor bus and Birney Safety Car, but as the work progressed it seemed advisable to include the trolley bus as well - a method of transportation that is comparatively new as far as development is concerned, but which seems to be finding increasing favor in the East.

Modelización acústica del interior de un Tren de Alta Velocidad

[ES]El presente Trabajo de Fin de Grado, titulado ‘Modelización Acústica del Interior de un Tren de Alta Velocidad’, tiene como objetivo el análisis acústico a bajas frecuencias del habitáculo de un coche de un tren de alta velocidad. La temática ha sido elegida debido a la creciente presencia de trenes de alta velocidad en nuestro entorno, en los cuales el Control Acústico o de Ruidos es un aspecto muy importante para el confort del medio de transporte. Dentro de los ruidos por los que se ve afectado el tren, los de baja frecuencia son los más difíciles de tratar y controlar, y es por ello que van a constituir la línea de trabajo de este proyecto. La estructura de lo que se va a tratar en este proyecto es la siguiente: En primer lugar, se analizará el contexto en que se encuadra este proyecto y las razones que han llevado a su realización. Posteriormente, se explicarán los fundamentos teóricos que hay detrás de los análisis que se van a realizar. Más adelante se pasará al análisis del caso práctico que se ha elegido para ilustrar el proyecto: el habitáculo de un coche del tren Serie 120 de Renfe, construido por CAF [1, 2, 3]. Se realizarán tanto análisis modales como de respuesta forzada. Dicho ejemplo servirá de base para asentar las conclusiones y proponer la aplicación que se les puede dar a éstas, así como las líneas de investigación para las cuales este proyecto puede ser un punto de partida.

Design of a timber Howe truss highway bridge

The span of the bridge was assumed as 100 feet. The type of bridge used is the timber Howe Truss. The height of truss was taken as 20 feet between center lines of top and bottom chords. The width was taken as 18 feet center to center of trusses. The truss was divided up into five panels 20 feet long.

It was designed according to the "General Specifications for Steel Highway Bridges" by Ketchum. For the live load for the floor and its supports, a load of 80 pounds per square foot of total floor surface or a 15 ton traction engine with axles 10 feet centers and 6 feet gage, two thirds of load to be carried by rear axles.

For the truss a load of 75 pounds per square foot of floor surface.

For the wind load the bottom lateral bracing is to be designed to resist a lateral wind load of 300 pounds per foot of span; 150 pounds of this to be treated as a moving load.

The top lateral bracing is to be designed to resist a lateral wind force of 150 pounds per foot of span.

The timber to be used in the bridge is to be Douglas fir.

The unit stresses used for timber are those of the American Railway Engineering Association.

Estimação de velocidade de composições usando processamento de vídeo

Esta dissertação tem como objetivo estudar um método para estimar a velocidade de veículos ferroviários usando processamento de vídeo. O sistema proposto consiste na utilização de câmeras ao longo das vias férreas que permitam não só o monitoramento do tráfego ferroviário, mas cujo vídeo captado possa ser utilizado para a obtenção de estimativas para a velocidade instantânea dos trens que por ela trafegam. Tal sistema seria utilizado independentemente dos sistemas de controle já utilizados pela operadora do sistema ferroviário, permitindo que os controladores possam ter uma segunda análise no caso de falha da primeira, assim como um modelo que permita avaliar a velocidade instantânea do veículo ferroviário ao longo do percurso. Os algoritmos de rastreamento empregados para esse fim abordaram diferentes métodos. Confrontaram-se os resultados obtidos com os algoritmos propostos com os dados empíricos de forma a determinar aquele com melhor resposta dada as características do sistema. O algoritmo que apresentou os melhores resultados emprega um único bloco de referência para todos os quadros comparados. A métrica de similaridade responsável por determinar quais blocos são mais ou menos similares dentro do universo de busca estipulado é a soma de diferenças absolutas (SAD, Sum of Absolute Differences). O tempo de processamento requerido por cada um dos métodos de rastreamento estudados também foi considerado nas avaliações de resultados apresentadas. Uma comparação realizada entre as velocidades coletadas e aquelas informadas pelo sistema de controle mostraram que os resultados obtidos com o sistema atual, utilizando a sinalização apenas por circuito de via apresenta resultados pouco confiáveis com erros bastante significativos. Os resultados obtidos com o sistema proposto apresentaram erros menores quando comparados àqueles obtidos pelo sistema vigente, apresentando-se assim como uma solução viável e de baixo custo quando comparada às técnicas atualmente empregadas para a medida de velocidade de trens.

Modelización acústica del interior de un tren de alta velocidad.

[ES]El presente Trabajo de Fin de Grado titulado 'Modelización Acústica del Interior de un Tren de Alta Velocidad' tiene como tarea la realización de diversos análisis acústicos de un habitáculo de un coche ferroviario. El principal objetivo va a ser ofrecer una guía detallada a modo de manual de usuario para llevar a cabo dichos análisis sin necesitar información adicional. Las herramientas de ayuda a utilizar van a ser un programa CAD de diseño como Solid Edge ST6 o Catia V5 y un software de elementos finitos como Ansys.

Modelling and Simulation of ERTMS for Current and Future Mobile Technologies

Nowadays, train control in-lab simulation tools play a crucial role in reducing extensive and expensive on-site railway testing activities. In this paper, we present our contribution in this arena by detailing the internals of our European Railway Train Management System in-lab demonstrator. This demonstrator is built over a general-purpose simulation framework, Riverbed Modeler, previously Opnet Modeler. Our framework models both ERTMS subsystems, the Automatic Train Protection application layer based on movement authority message exchange and the telecommunication subsystem based on GSM-R communication technology. We provide detailed information on our modelling strategy. We also validate our simulation framework with real trace data. To conclude, under current industry migration scenario from GSM-R legacy obsolescence to IP-based heterogeneous technologies, our simulation framework represents a singular tool to railway operators. As an example, we present the assessment of related performance indicators for a specific railway network using a candidate replacement technology, LTE, versus current legacy technology. To the best of our knowledge, there is no similar initiative able to measure the impact of the telecommunication subsystem in the railway network availability.

ETCS protokoloaren hedatzea simulazio hibridodun ingurune batean System-in-the-loop erreminta erabiliz.

[EU]Gaur egun, Europa mailan European Rail Traffic Management System (ERTMS) seinaleztapen-sistema bateratua hedatzen ari dira trenbide sare desberdinen arteko elkar eragintasuna bultzatzeko. Proiektu honen helburua da ERTMS sistemaren barneko ETCS protokoloa hedatzea simulazio hibridodun ingurune batean, ERTMS sistemaren hedatzea azkartuko duten erakusleak sortuz. Horretarako, OPNET simulagailuaren System-in-the-loop erreminta erabili da. Erreminta hau baliatuz ETCS protokoloaren pakete errealak ingurune simulatuan integratzeko funtzioen liburutegi bat idatzi da. Amaitzeko, liburutegi hori baliatuz ETCS protokoloak sareko arazoen aurrean duen errendimenduaren analisi bat burutu da eta liburutegi berri horrek pakete errealak simulatuetara itzultzean (eta kontrakoa) duen errendimendua zein den aztertu da.

Implementación de sistema ETCS en entorno cliente-servidor.

[ES]La interoperabilidad entre distintas redes ferroviarias europeas es muy escasa. Para dar solución a este problema, la Unión Europea creó el sistema europeo de gestión del tráfico ferroviario (ERTMS), encargado de crear un estándar único para toda la red europea. El objetivo de este proyecto es la implementación del sistema ETCS ( European Train Control System ) en un entorno cliente-servidor. La implementación incluye el sistema del tren y el del centro de control (RBC). Se ha implementado de forma que se pueda operar sobre dos protocolos de red transporte, de forma que será compatible tanto para redes orientadas a la conexión (TCP) como no orientadas a conexión (UDP).

Do outro lado da linha do trem, havia uma pedra no meio do caminho: um estudo sobre crack no Rio de Janeiro na perspectiva da Teoria Ator-rede

O objetivo dessa pesquisa é discutir o cenário de uso de crack no município do Rio de Janeiro contextualizado com a condição de vulnerabilidade e risco social, através do mapeamento das controvérsias entre os atores dessa rede. As percepções e experiências relatadas neste trabalho dizem respeito aos diferentes espaços profissionais voltados ao atendimento e prestação de serviço a este público. Inicialmente, é trazida a trajetória teórica e prática que levaram a construção desta dissertação. Foram relatadas experiências vividas nas ações conjuntas de abordagem com a SMDS (Secretaria Municipal de Desenvolvimento Social) e a prática como entrevistadora de usuários de crack na Pesquisa Nacional do Crack pela FIOCRUZ. No segundo momento, é feito um breve histórico da origem do crack e suas marcas pelo mundo. São trazidos também, dados sobre a droga no Brasil, em particular sua história no Rio de Janeiro. Ainda nesta sequência, é apresentada a política de Redução de Danos, mostrando de que maneira o sujeito é significado a partir dessa perspectiva, e suas principais contribuições pelo mundo e também no país. A dissertação é construída pela perspectiva das práticas profissionais do psicólogo SMDS pensada através da Teoria Ator-rede. Foi importante destacar as principais ações de política pública voltadas para essa temática, considerando os avanços na discussão da temática. Foram mapeadas e exploradas as relações entre os atores envolvidos nesta temática (usuários de crack, SMDS, SMS Secretaria Municipal de Saúde, Segurança Pública, Mídia, Sociedade), colocando em evidencia as controvérsias existentes nessas relações, como recolhimento compulsório. De maneira conclusiva, são trazidas as impressões tiradas ao final deste percurso, problematizando os papéis do poder público e daqueles que atuam para garantir a população que faz uso abusivo de crack e outras drogas o direito de acessar e exercia sua cidadania.

A three-dimensional tunnel model for calculation of train-induced ground vibration

The frequency range of interest for ground vibration from underground urban railways is approximately 20 to 100 Hz. For typical soils, the wavelengths of ground vibration in this frequency range are of the order of the spacing of train axles, the tunnel diameter and the distance from the tunnel to nearby building foundations. For accurate modelling, the interactions between these entities therefore have to be taken into account. This paper describes an analytical three-dimensional model for the dynamics of a deep underground railway tunnel of circular cross-section. The tunnel is conceptualised as an infinitely long, thin cylindrical shell surrounded by soil of infinite radial extent. The soil is modelled by means of the wave equations for an elastic continuum. The coupled problem is solved in the frequency domain by Fourier decomposition into ring modes circumferentially and a Fourier transform into the wavenumber domain longitudinally. Numerical results for the tunnel and soil responses due to a normal point load applied to the tunnel invert are presented. The tunnel model is suitable for use in combination with track models to calculate the ground vibration due to excitation by running trains and to evaluate different track configurations. © 2006 Elsevier Ltd. All rights reserved.

Ground vibration generated by trains in underground tunnels

A popular method used to reduce vibration transmitted from underground railways into nearby buildings is floating-slab track, whereby a concrete slab supporting the two rails is mounted on rubber bearings or steel springs to isolate it from the tunnel invert. This paper adds a track model to a previously developed three-dimensional tunnel model in order to assess the effectiveness of floating-slab track. A slab beam coupled to the tunnel in the wavenumber domain, with the slab bearings represented by an elastic layer, is examined first. A second beam representing the two rails together is then coupled to the slab, and axle masses representing a train are added to the rail beam. Power-spectral densities and RMS levels of soil vibration due to random roughness-displacement excitation between the masses and the rail beam are calculated. Analytical techniques are used to minimise the computational requirements of the model. The results demonstrate the inadequacy of simple mass-spring and Winkler-beam models with rigid foundations for the assessment of the vibration-isolation performance of railway track. They suggest that the achievable insertion loss is modest and that floating the track slab may in fact cause increased transmission of vibration under certain conditions. © 2006 Elsevier Ltd. All rights reserved.

Ecological impact of Mahshahr petrochemical activities on abundance and diversity of macrobenthic fauna in Zangi Creek (Persian Gulf)

The Moosa Creek extends from its opening into the Persian Gulf, with some sub narrow creeks leading to it. Zangi creek is one of the main branches of Moosa creek. The creek contains numerous sources of organic pollution, including sewage outlet flows and boat waste. After establishing the Petrochemical special Economic Zone (PETZONE) in 1997 near to the Zangi Creek, the pipelines, streets and railway made it distinct from eastern and western parts of this creek. Industrial activities have released sludge and effluents in this creek along these years. A survey of the Zangi creek was performed, assessing water properties, organic pollution, and the population density, distribution and diversity of macrobenthic fauna through bi-monthly sampling from July 2006 to September 2007. Samples were collected from water near the bottom and sediment at 7 stations include 2 stations inside the distinct Zangi creek and 4 stations along a transect with 1 km distances between them in eastern free part and one reference station located at the Persian Gulf entrance to the Moosa creek. The environmental parameters such as temperature, salinity, pH, dissolved oxygen, COD, turbidity, EC and heavy metals include Hg, Cd, Pb, Ni as well as percentage silt-clay and total organic matter of the sediment were measured. The faunal population density and their distribution are discussed in relation to the environmental changes. Results showed spatial heterogeneity in faunal distribution of the Zangi creek. Nine groups of macrofauna were identified out of distinct zangi creek. Polychaets formed the dominant group (48%) followed by bivalves (13%), gastropods (10%), Decapods (2%), Tanaids (5%), and all other groups (22%). The distinct creek was heavily polluted without any macrofauna communities probably as a consequence of the high pH, COD, low salinity and heavy metals contamination specially Cd and Pb. The other stations near to the disposal site were found with macrofauna communities commonly tolerant to organic pollution, At 3 km east of the disposal site, macrofauna is comparable to the surrounded creek, whereas macrofauna still indicate environmental degradation. Farther a way, faunal density decreases and equilibrium taxa gradually replace opportunistic species, while the other stations were far from polluted area contained lower pollution and relatively healthy macrofauna. The mean biomass of macrobenthic fauna were estimated for the whole studied area. The results are considered in Minimum density and biomass in surrounded creek and maximum density and biomass in 3 km of surrounded area. Biodiversity Indices were low in surrounded creek. The Shanon-weaver information index was used to describe the spatially variations in diversity. Macrofauna density, shanon and simpson index were significantly variable between surrounded and free parts of Zangi creek (p<0.05). The numerical abundance of macrobenthose varied from 221. m-2 in polluted area to 4346 m-2 in free part of Zangi creek. The Shanon-weaver information index varied from 0.4 in distinct area to 2.9 in reference station. The physico- chemical changes between distinct and free creeks showed significant variations such as pH, salinity and EC. Salinity and EC were significantly positive correlate to macrofauna density, whereas pH and TOM percentage indicated significantly negative correlation to density. Heavy metals concentrations in sediments were higher than water samples. Concentration pattern of heavy metals in sediments and water samples were Ni>Pb>Cd>Hg. Salinity and pH were significantly correlated to metals in sediments (p<0.01). No significant correlation were found between Macrofauna density and heavy metals (p<0.05).