Browsing by Author "Giesen Encina, Ricardo"
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- ItemA method for solving the multi-objective transit frequency optimization problem(2016) Giesen Encina, Ricardo; Martínez, H.; Mauttone, A.; Urquhart, M.
- ItemA method to determine container seaport hinterlands(2018) Mac Cawley Vergara, Alejandro Francisco; Vega, Javier N.; Florez Calderón, Luz Angela; Giesen Encina, Ricardo
- ItemA method to determine container seaport hinterlands(2018) Mac Cawley Vergara, Alejandro Francisco; Vega, Javier N.; Florez Calderón, Luz Angela; Giesen Encina, Ricardo
- ItemAn analysis of service level impact on delivery cost routing with time windows.(2012) Burq, Philippe; Giesen Encina, Ricardo; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
- ItemAn integrated approach for timetabling and vehicle scheduling problems to analyze the trade-off between level of service and operating costs of transit networks(2014) Ibarra Rojas, Omar, J.; Giesen Encina, Ricardo; Ríos Solis, Yasmin, A.
- ItemAnalysis of real-time control strategies in a corridor with multiple bus services(2015) Hernández, D.; Muñoz Abogabir, Juan Carlos; Giesen Encina, Ricardo; Delgado Breinbauer, Felipe Alberto
- ItemAplicación de algoritmos de aprendizaje estadístico para predecir velocidades de buses con información en tiempo real(2015) Julio Alessandrini, Nikolas; Giesen Encina, Ricardo; Pontificia Universidad Católica de Chile. Escuela de IngenieríaLa predicción de velocidad de buses de transporte público es relevante tanto para los usuarios como los operadores. Para los usuarios permite generar herramientas que le entreguen información certera sobre aproximación del próximo bus, así como también ayuda en la elección de rutas expeditas según la hora del día. Para los operadores es relevante al momento de planificar recorridos, frecuencias u horarios. Hay literatura de casos exitosos de predicción de velocidad en tiempo real usando algoritmos de aprendizaje estadístico, pero cada trabajo es distinto y son poco comparables debido a la diferencia entre los datos disponibles usados. En este caso, los datos usados corresponden a pulsos de GPS transformados en velocidades. No se encontró bibliografía con los mismos tipos de datos, por lo que consideramos que este caso es nuevo. Así, el objetivo de este trabajo es comparar el desempeño de distintos algoritmos de aprendizaje estadístico incorporando información en tiempo real de dispositivos GPS para predecir velocidades de buses en la ciudad de Santiago de Chile.Se usarán tres algoritmos de aprendizaje estadístico: redes neuronales, máquinas de soporte vectorial y redes bayesianas, de los que se generan cuatro modelos. Éstos se comparan entre sí, además de con dos modelos benchmark, siendo testeados en tres servicios de buses: 501-ida, C06-ida y 210-ida de Transantiago, el sistema de transporte público de Santiago. El documento abarca desde el procesamiento previo de las velocidades, que son obtenidas a través de pulsos enviados por GPS equipados en los buses, hasta el detalle de cada modelo junto a sus parámetros, mostrando posteriormente los resultados y un análisis de éstos. Basados en este caso de estudio, se concluye que el algoritmo de redes neuronales es el que mejor desempeño muestra con nuestro set de datos, logrando una mejora de hasta 23% sobre la raíz del error cuadrático medio con respecto al mejor de los modelos benchmark. Dado que sólo se contaba con información de GPS, se propone incluir variables explicativas adicionales, como flujo vehicular de espiras magnéticas, información de abordaje de sistemas de pago de tarifas (FCS, Fare Collecting Systems), o información de incidentes en las vías.
- ItemBRRT adding an R for reliability(Policy Press, 2016) Delgado Breinbauer, Felipe Alberto; Giesen Encina, Ricardo; Munoz, Juan Carlos
- ItemBus Control Strategy Application : Case Study of Santiago Transit System(2014) Lizana, Pedro; Muñoz Abogabir, Juan Carlos; Giesen Encina, Ricardo; Delgado Breinbauer, Felipe Alberto
- ItemBus Rapid Transit: End of trend in Latin America?(Cambridge University Press, 2024) Hidalgo D.; Giesen Encina, Ricardo; Muñoz, Juan CarlosBus Rapid Transit (BRT) has grown fast in the last 25 years, promising low-cost, rapid implementation, and large positive impacts. Despite advances, many systems in middle- and low-income countries face operational and financial issues, particularly in Latin America. Some practitioners, researchers, and decision makers, and the media are questioning its ability to provide quality services. Is this the end of a trend? To answer this question, this paper explores the status of the BRT industry and literature on the topic, with a focus on Latin America, as well as the emblematic cases of Curitiba, Quito, Bogotá, Mexico, and Santiago. Overcrowding, lack of reliability, fare evasion, issues of safety and security, and poor maintenance are evident problems in these and other cities. They seem to be a result of institutional and financial constraints, as well as technical limitations of surface-based transit modes. BRT has been able to deliver high-capacity and fast and reliable services, but requires permanent management and investment to face growing demand and aging infrastructure and vehicles, just like rail systems do. In addition, attention needs to be provided to data, technology innovation, urban integration, and public participation to keep BRT as an integral part of multimodal high-quality sustainable mobility networks in the future.
- ItemComparison of dynamic control strategies for transit operations(2013) Muñoz Abogabir, Juan Carlos; Cortés, Cristián E.; Giesen Encina, Ricardo; Sáez, Doris; Delgado Breinbauer, Felipe Alberto; Valencia, Francisco; Cipriano, Aldo
- ItemContinuous approximation for skip-stop operation in rail transit(2013) Freyss, Maxime; Giesen Encina, Ricardo; Muñoz Abogabir, Juan Carlos
- ItemDesigning integrated urban delivery systems using public transport(Elsevier Ltd, 2021) Azcuy Fuentes, Irecis Lazara; Agatz, Niels; Giesen Encina, RicardoThe growth of online retail leads to increasing last-mile delivery operations that contribute to various negative externalities, such as traffic congestion and air pollution, especially in urban areas. One way to improve urban delivery operations is to use public transport capacity to move goods to intermediate transfer locations from which they can be delivered by (small) vehicles to the final customers. We study the distance savings that can be achieved by such a two-tier urban delivery system. In particular, we focus on determining which transit stop is best located to be used as a transfer location. We present several special cases to get insights into the transfer location decisions. Moreover, we present a mixed-integer linear programming formulation and a heuristic to solve it. To evaluate the different approaches, we run several computational studies. We also perform a sensitivity analysis to assess the impact of different system parameters on the location decisions and system performance. For very conservative benchmarks, the results show that savings up to 7.1 percent are possible from using public transport capacity to support urban delivery. The savings increase with the distance to the depot, tighter deadlines and customers that are clustered around the transit line.
- ItemDetermination of efficient frontiers for urban public transport system configurations(2023) Basnak Klajn, Paul Alexander; Giesen Encina, Ricardo; Muñoz Abogabir, Juan Carlos; Pontificia Universidad Católica de Chile. Escuela de IngenieríaOne of the fundamental aspects when planning an urban public transport system is to define which modes provide the greatest benefit both for the city residents and for the system operators. Two relevant questions arise from this: What characteristics of cities and their people are relevant to define these modes? What are the efficiency frontiers – that is, the minimum and maximum values of these relevant characteristics – for the different modal configurations that an urban public transport system should have? The available literature addresses these questions through recommendations based on existing systems and mathematical optimization models. However, recommendations based on existing systems are often limited to simple criteria based on the population of cities an the income of their residents, which ignores the relevance of other factors explaining public transport trips in lines or networks. For their part, optimization models have been widely used to define the ideal fundamental characteristics that a given transport service or network should have, such as frequency, density of lines and distance between stops, but they usually lack in linking the real characteristics of cities with the transport technologies that allow minimizing total costs. In addition, there are no known systematic efforts to link both mentioned approaches, considering the behaviour of people in their mode choice. The general objective of this research is to develop classification and optimization models to recommend which public transport modes a city should have according to their basic characteristics. Moreover, the proposed models are applied in simple representations of cities with low-capacity modes and in transit lines with high-capacity modes. Based on this general aim, the main objectives are the following: a) Estimate aggregate classification models at the city level to determine which geographic and socioeconomic factors of cities and their residents define the existing modal supply in their public transport systems. b) Provide recommendations about the set of modes to be used in cities below 200,000 inhabitants, by applying social cost minimization models in simplified representations of such cities. c) Propose improved demand thresholds that set the recommendation between high-capacity modes (bus, Bus Rapid Transit [BRT], Metro) through optimization models in transit lines. To achieve this objective, a stated preference study was first performed, which allowed for improving the perception of the penalty for crowding in public transport vehicles. Once these valuations were obtained, cost minimization models were applied in corridors to update the demand thresholds to allow a better selection of the most efficient technology. In conclusion, we identified common determinants of higher capacity transit modes in cities, both for the existing and recommended systems, such as a higher population, income, and linear form. From the onset of COVID-19, users were found to penalize traveling in crowded transit vehicles with non-linear functions increasing with density of passengers in the vehicle and the proportion of users not wearing facemasks. When applying these valuations to line optimization models, the minimum demand that justifies building a BRT over a standard bus line is reduced when facemask use compliance is lower, and directionality of demand is less significant than if pre-pandemic values were used.
- ItemEnfoque de optimización para la transición desde jornadas parciales a jornadas completas en un sistema escolar(2017) Pavez van Rysselberghe, Tomás Ignacio; Giesen Encina, Ricardo; Pontificia Universidad Católica de Chile. Escuela de IngenieríaPara implementar la transición de un sistema de jornada parcial escolar a uno de jornada completa se deben realizar mejoras de infraestructura a las escuelas. Uno de los desafíos es minimizar la disrupción de la educación de los alumnos que tendrán que ser transferidos y a la vez minimizar los costos y el tiempo de transición. El trabajo desarrollado en esta tesis consiste en elaborar un modelo de programación entero mixto que permita entregar un plan para realizar la mejor transición posible de la situación actual a una situación óptima dada. Dado que la solución de este modelo implica un costo computacional considerable, se programó una heurística basada en el algoritmo GRASP para encontrar una solución inicial factible cercana al óptimo para dársela como punto de partida al software de optimización y así alcanzar el óptimo en tiempos razonables. El método propuesto fue probado con datos reales de dos municipios brasileños: Axixa y Timón. Los resultados mostraron que la decisión de qué colegio abrir y cuándo abrirlo es robusta sobre la estimación de alumnos futuros. Además incluir el costo subjetivo de cambiar un alumno de colegio en la función objetivo puede mejorar notoriamente los niveles de servicio sin aumentar de manera importante los costos monetarios. Finalmente, el uso de una heurística GRASP para alcanzar una solución inicial reduce el tiempo de resolución desde más de cuatro semanas hasta menos de diez minutos. Además, para los casos estudiados, la heurística puede alcanzar soluciones que están a menos del 5% del óptimo.
- ItemEstimation and prediction of dynamic matrix travel on a public transport corridor using historical data and real-time information(2020) Zúñiga Artigas, Felipe Andrés; Muñoz Abogabir, Juan Carlos; Giesen Encina, Ricardo
- ItemUna formulación para el problema de ruteo de vehículos con tiempos de viaje dependientes del tiempo para la actualización de rutas con información en tiempo real(2009) Ebensperger Palacios, Matías Jaime; Giesen Encina, Ricardo; Fernández Larrañaga, José Enrique; Pontificia Universidad Católica de Chile. Escuela de IngenieríaEn esta investigación se estudia el problema de ruteo dinámico de vehículos con ventanas de tiempo e información en tiempo real respecto de las condiciones de oferta y demanda del sistema. Los objetivos de la presente investigación son: (i) cuantificar los beneficios del uso de tiempos de viaje dependientes del tiempo en la construcción de rutas de despacho vehiculares; (ii) cuantificar los beneficios del uso de información en tiempo real para actualizar planes en la operación de rutas de despacho vehiculares, considerando cambios en los niveles de servicio de la red de transporte, y nuevas demandas; y (iii) desarrollar un algoritmo de solución para el problema. Se construyó una red espacio-tiempo para reflejar la condición de tiempos de viaje dependientes del tiempo.
- ItemGeneration and design heuristics for zonal express services(2015) Larraín Izquierdo, Homero; Muñoz Abogabir, Juan Carlos; Giesen Encina, Ricardo
- ItemHow many Urban Recycling Centers do We Need and where? A Continuum Approximation Approach(2016) Soto, Javier; Muñoz Abogabir, Juan Carlos; Giesen Encina, Ricardo
- ItemHow much can holding and/or limiting boarding improve transit performance?(PERGAMON-ELSEVIER SCIENCE LTD, 2012) Delgado Breinbauer, Felipe Alberto; Muñoz Abogabir, Juan Carlos; Giesen Encina, RicardoBus bunching affects transit operations by increasing passenger waiting times and its variability. This work proposes a new mathematical programming model to control vehicles operating on a transit corridor minimizing total delays. The model can handle a heterogeneous fleet of vehicles with different capacities without using binary variables, which make solution times compatible with real-time requirements. Two control policies are studied within a rolling horizon framework: (i) vehicle holding (HRT), which can be applied at any stop and (ii) holding combined with boarding limits (HBLRT), in which the number of boarding passengers at any stop can be limited in order to increase operational speed. Both strategies are evaluated in a simulation environment under different operational conditions. The results show that HBLRT and HRT outperform other benchmark control strategies in all scenarios, with savings of excess waiting time of up to 77% and very low variability in performance. HBLRT shows significant benefits in relation to HRT only under short headway operation and high passenger demand. Moreover, our results suggest implementing boarding limits only when the next arriving vehicle is nearby. Interestingly, in these cases HBLRT not only reduces an extra 6.3% the expected waiting time in comparison with HRT, but also outperforms other control schemes in terms of comfort and reliability to both passengers and operators. To passengers HBLRT provide a more balanced load factor across vehicles yielding a more comfortable experience. To operators the use of boarding limits speed up vehicles reducing the average cycle time and its variability, which is key for a smooth operation at terminals. (C) 2012 Elsevier Ltd. All rights reserved.