David Canca | Universidad de Sevilla (original) (raw)
Papers by David Canca
2015 International Conference on Industrial Engineering and Systems Management (IESM), 2015
RESUMEN Este trabajo presenta un nuevo modelo dinámico de distribución y asignación de flujos pea... more RESUMEN Este trabajo presenta un nuevo modelo dinámico de distribución y asignación de flujos peatonales (Dynamic Distribution and Assignment Simulation – DDAS-Model) basado en técnicas de simulación en tiempo discreto y en asignación dinámica de rutas. A diferencia del modelo clásico de planificación de transporte en cuatro etapas, el modelo propuesto incorpora las etapas de distribución y asignación de forma entrelazada y dinámica a lo largo de un horizonte específico de tiempo, y por tanto no caracteriza la demanda de forma explicita como matrices origen-destino de desplazamientos. En cada instante, los individuos que deben comenzar nuevos desplazamientos intentan minimizar su tiempo de viaje hacia destinos que les son interesantes bajo la hipótesis de búsqueda de un equilibrio de usuario que no llega a producirse dado el carácter dinámico del proceso. El modelo permite el estudio en detalle de importantes eventos expositivos (ferias y exposiciones internacionales) y se aplica a ...
Las Enfermedades Raras en la Unión Europea, representan alrededor del 7% de los europeos, 51 mill... more Las Enfermedades Raras en la Unión Europea, representan alrededor del 7% de los europeos, 51 millones de personas. Dichas enfermedades requieren de esfuerzos especiales para poder combatirlas. Se estima, que alrededor de 4000 de estas enfermedades no tienen tratamientos curativos. Los afectados por enfermedades raras no han tenido las mismas oportunidades que otros pacientes con enfermedades más comunes, en las que existen en la mayoría de los casos grandes avances y estudios que aportan una cura de dicha enfermedad o palían en gran medida los síntomas que sufren, incrementando enormemente el nivel de vida de los afectados. Con el objeto de ayudar en la investigación (origen, evolución y tratamiento) de dichas enfermedades se ha creado el proyecto ER2.0, patrocinado por la Cátedra Avenzoar (Universidad de Sevilla), que sirve de marco común para recopilar información on-line sobre las enfermedades y sus pacientes. En el presente trabajo se aborda la explotación de dicha información c...
Annals of Operations Research, 2015
In the coming years the implementation of regulations for water suppliers are expected. Member st... more In the coming years the implementation of regulations for water suppliers are expected. Member states of the EEC (European Economic Community) need to use telematics systems for reading the water consumption. The supplier companies are now developing and valuing the different technical solutions to address this issue. One of the proposed alternatives is by placing a transmitter on the walls of buildings with access to digital counters of subscribers. This transmitter sends the signal to a repeater (single router or multiple in cascade) until the signal reaches the company network. The problem can be classified as Capacitated Multiple Hub Location Problem with constraints in both arcs and nodes (see e.g. Campbell 1994 and Alumur and Kara, 2008). In our study the problem of locating the routers that comprise the network is addressed by studying two different technological alternatives for installation. The characteristics of two alternatives and has been modeled by a MIP model (Rodríg...
This paper presents an approximate procedure to solve a multi-commodity capacitated network flow ... more This paper presents an approximate procedure to solve a multi-commodity capacitated network flow problem with concave routing costs, considering also outsourcing, overload and underutilization facility costs. The model is derived from a real NP production, inventory management and transportation problem concerning to the Andalusian Regional Network of Clinical Laboratories (RNCL). In order to speed up the solving procedure, the inherent non-convex modified all-unit discount problem is approximately solved by a sequential two-phase modelling approach. Numerical results obtained from two different instances are reported.
The k-shortest path (KSP)-problem is a classical problem with many applications in flow networks a... more The k-shortest path (KSP)-problem is a classical problem with many applications in flow networks and optimization. The problem was ini- tially studied in 1959 by Hoffman and Pavley but the fastest KSP al- gorithm was developed by Eppstein in 1988. In this work we provide a review of the shortest path problem algorithms (commonly used as a starting point for developing the KSPs algorithms) and revise the main techniques for determining the KSPs. Thirdly, we analyze the suitabil- ity of these algorithms to the context of railway transportation from both user and operator perspectives.
Este trabajo presenta parte de un modelo de simulación microscópica desarrollado para el modelado... more Este trabajo presenta parte de un modelo de simulación microscópica desarrollado para el modelado de redes urbanas reguladas mediante sistemas de control de tráfico. El simulador microscópico contempla el viario con un alto grado de detalle, simulando el comportamiento de cada vehículo mediante nuevos modelos de aceleración y cambio de carril. Así mismo incorpora un novedoso modelo de aparcamiento que permite estudiar el impacto de los vehículos y su influencia en el viario en cuestión de aparcamientos. El modelo de selección de rutas está basado en el estudio de los porcentajes de vehículos que realizan un giro y que determina indirectamente los tipos de cambio de carril que se pueden realizar. El simulador ha sido diseñado mediante metodología orientada a objetos (UML, lenguaje de modelado unificado) y la implementación ha sido realizada en C++. El artículo se centra en la estructura del modelo de cambio de carril desarrollado en el simulador.
After three decades of using the circular four-stage model for transportation planning, the lates... more After three decades of using the circular four-stage model for transportation planning, the latest developments in this area have been focused on improving the algorithms used to solve the assignment stage, the use of logit and probit models increasingly sophisticated for the determination of modal split, the emergence of dynamic equilibrium models and new equilibrium concepts that generalize the widely used and defined by Wardrop. Basically the planning process starts with the definition of a set of scenarios (mobility supply). The different stages are applied sequentially to each one and finally, the modeler has to select the solution that he believe more appropriate in terms of travel times and congestion. This paper presents a new private mode assignment model to simultaneously determine traffic assignment and links capacity. That is, the model solution proposes optimal travel routes between each origin-destination pair and the optimal configuration of the network. In this way t...
The theoretical capacity of a railway line is defined as the maximum number of trains that can tr... more The theoretical capacity of a railway line is defined as the maximum number of trains that can travel on each of the directions during a given time interval, subject to safety conditions. The set of actions that enable to increase the capacity of railway infrastructures can be classified into two main groups: actions on the infrastructure, which belong to the context of long-term measures and usually require large initial investments, and actions on the exploitation, which are economically cheaper and applied in the short and medium term horizon. Belonging to the latter group, there are simple strategies to increase the railway lines capacity, such as speed homogenization, traffic management, selective selection of stops and the use of alternative routes. None of them requires as large financial investments as unfolding existing tracks. The radial - backbone (or X-tree) structure is one of the most widely used topological schemes in conventional railways and tramways in urban transp...
2015 International Conference on Industrial Engineering and Systems Management (IESM), 2015
RESUMEN Este trabajo presenta un nuevo modelo dinámico de distribución y asignación de flujos pea... more RESUMEN Este trabajo presenta un nuevo modelo dinámico de distribución y asignación de flujos peatonales (Dynamic Distribution and Assignment Simulation – DDAS-Model) basado en técnicas de simulación en tiempo discreto y en asignación dinámica de rutas. A diferencia del modelo clásico de planificación de transporte en cuatro etapas, el modelo propuesto incorpora las etapas de distribución y asignación de forma entrelazada y dinámica a lo largo de un horizonte específico de tiempo, y por tanto no caracteriza la demanda de forma explicita como matrices origen-destino de desplazamientos. En cada instante, los individuos que deben comenzar nuevos desplazamientos intentan minimizar su tiempo de viaje hacia destinos que les son interesantes bajo la hipótesis de búsqueda de un equilibrio de usuario que no llega a producirse dado el carácter dinámico del proceso. El modelo permite el estudio en detalle de importantes eventos expositivos (ferias y exposiciones internacionales) y se aplica a ...
Las Enfermedades Raras en la Unión Europea, representan alrededor del 7% de los europeos, 51 mill... more Las Enfermedades Raras en la Unión Europea, representan alrededor del 7% de los europeos, 51 millones de personas. Dichas enfermedades requieren de esfuerzos especiales para poder combatirlas. Se estima, que alrededor de 4000 de estas enfermedades no tienen tratamientos curativos. Los afectados por enfermedades raras no han tenido las mismas oportunidades que otros pacientes con enfermedades más comunes, en las que existen en la mayoría de los casos grandes avances y estudios que aportan una cura de dicha enfermedad o palían en gran medida los síntomas que sufren, incrementando enormemente el nivel de vida de los afectados. Con el objeto de ayudar en la investigación (origen, evolución y tratamiento) de dichas enfermedades se ha creado el proyecto ER2.0, patrocinado por la Cátedra Avenzoar (Universidad de Sevilla), que sirve de marco común para recopilar información on-line sobre las enfermedades y sus pacientes. En el presente trabajo se aborda la explotación de dicha información c...
Annals of Operations Research, 2015
In the coming years the implementation of regulations for water suppliers are expected. Member st... more In the coming years the implementation of regulations for water suppliers are expected. Member states of the EEC (European Economic Community) need to use telematics systems for reading the water consumption. The supplier companies are now developing and valuing the different technical solutions to address this issue. One of the proposed alternatives is by placing a transmitter on the walls of buildings with access to digital counters of subscribers. This transmitter sends the signal to a repeater (single router or multiple in cascade) until the signal reaches the company network. The problem can be classified as Capacitated Multiple Hub Location Problem with constraints in both arcs and nodes (see e.g. Campbell 1994 and Alumur and Kara, 2008). In our study the problem of locating the routers that comprise the network is addressed by studying two different technological alternatives for installation. The characteristics of two alternatives and has been modeled by a MIP model (Rodríg...
This paper presents an approximate procedure to solve a multi-commodity capacitated network flow ... more This paper presents an approximate procedure to solve a multi-commodity capacitated network flow problem with concave routing costs, considering also outsourcing, overload and underutilization facility costs. The model is derived from a real NP production, inventory management and transportation problem concerning to the Andalusian Regional Network of Clinical Laboratories (RNCL). In order to speed up the solving procedure, the inherent non-convex modified all-unit discount problem is approximately solved by a sequential two-phase modelling approach. Numerical results obtained from two different instances are reported.
The k-shortest path (KSP)-problem is a classical problem with many applications in flow networks a... more The k-shortest path (KSP)-problem is a classical problem with many applications in flow networks and optimization. The problem was ini- tially studied in 1959 by Hoffman and Pavley but the fastest KSP al- gorithm was developed by Eppstein in 1988. In this work we provide a review of the shortest path problem algorithms (commonly used as a starting point for developing the KSPs algorithms) and revise the main techniques for determining the KSPs. Thirdly, we analyze the suitabil- ity of these algorithms to the context of railway transportation from both user and operator perspectives.
Este trabajo presenta parte de un modelo de simulación microscópica desarrollado para el modelado... more Este trabajo presenta parte de un modelo de simulación microscópica desarrollado para el modelado de redes urbanas reguladas mediante sistemas de control de tráfico. El simulador microscópico contempla el viario con un alto grado de detalle, simulando el comportamiento de cada vehículo mediante nuevos modelos de aceleración y cambio de carril. Así mismo incorpora un novedoso modelo de aparcamiento que permite estudiar el impacto de los vehículos y su influencia en el viario en cuestión de aparcamientos. El modelo de selección de rutas está basado en el estudio de los porcentajes de vehículos que realizan un giro y que determina indirectamente los tipos de cambio de carril que se pueden realizar. El simulador ha sido diseñado mediante metodología orientada a objetos (UML, lenguaje de modelado unificado) y la implementación ha sido realizada en C++. El artículo se centra en la estructura del modelo de cambio de carril desarrollado en el simulador.
After three decades of using the circular four-stage model for transportation planning, the lates... more After three decades of using the circular four-stage model for transportation planning, the latest developments in this area have been focused on improving the algorithms used to solve the assignment stage, the use of logit and probit models increasingly sophisticated for the determination of modal split, the emergence of dynamic equilibrium models and new equilibrium concepts that generalize the widely used and defined by Wardrop. Basically the planning process starts with the definition of a set of scenarios (mobility supply). The different stages are applied sequentially to each one and finally, the modeler has to select the solution that he believe more appropriate in terms of travel times and congestion. This paper presents a new private mode assignment model to simultaneously determine traffic assignment and links capacity. That is, the model solution proposes optimal travel routes between each origin-destination pair and the optimal configuration of the network. In this way t...
The theoretical capacity of a railway line is defined as the maximum number of trains that can tr... more The theoretical capacity of a railway line is defined as the maximum number of trains that can travel on each of the directions during a given time interval, subject to safety conditions. The set of actions that enable to increase the capacity of railway infrastructures can be classified into two main groups: actions on the infrastructure, which belong to the context of long-term measures and usually require large initial investments, and actions on the exploitation, which are economically cheaper and applied in the short and medium term horizon. Belonging to the latter group, there are simple strategies to increase the railway lines capacity, such as speed homogenization, traffic management, selective selection of stops and the use of alternative routes. None of them requires as large financial investments as unfolding existing tracks. The radial - backbone (or X-tree) structure is one of the most widely used topological schemes in conventional railways and tramways in urban transp...