AZ
A.A. Zilko
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5 records found
1
Journal article
(2018)
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Nadjla Ghaemi, Aurelius Zilko, Fei Yan, Oded Cats, Dorota Kurowicka, Rob Goverde
Disruptions such as rolling stock breakdown, signal failures, and accidents are recurrent events during daily railway operation. Such events disrupt the deployment of resources and cause delay to passengers. Obtaining a reliable disruption length estimation can potentially reduce the negative impact caused by the disruption. Different factors such as the location, cause of disruption, traffic density, etc. can determine the disruption length. The uncertainty inherent to the variability of each factor and the unavailability of sufficient data results in a wide distribution of disruption lengths from which a certain value should be selected as the length prediction. The rescheduling measure considered in this research is short-turning the trains that are heading to the disrupted area. To investigate the impact of the disruption length estimates on the rescheduling strategy and the resulting passengers delays, this research presents a framework consisting of three models: a disruption length model, short-turning model and passenger assignment model. The framework is applied to a part of the Dutch railway network. The results show the effects of short (optimistic) and long (pessimistic) estimates on the number of affected passengers, generalized travel time and number of passengers rerouting and transferring.
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Disruptions such as rolling stock breakdown, signal failures, and accidents are recurrent events during daily railway operation. Such events disrupt the deployment of resources and cause delay to passengers. Obtaining a reliable disruption length estimation can potentially reduce the negative impact caused by the disruption. Different factors such as the location, cause of disruption, traffic density, etc. can determine the disruption length. The uncertainty inherent to the variability of each factor and the unavailability of sufficient data results in a wide distribution of disruption lengths from which a certain value should be selected as the length prediction. The rescheduling measure considered in this research is short-turning the trains that are heading to the disrupted area. To investigate the impact of the disruption length estimates on the rescheduling strategy and the resulting passengers delays, this research presents a framework consisting of three models: a disruption length model, short-turning model and passenger assignment model. The framework is applied to a part of the Dutch railway network. The results show the effects of short (optimistic) and long (pessimistic) estimates on the number of affected passengers, generalized travel time and number of passengers rerouting and transferring.
The uncertainty of railway disruption length hinders the performance of the Operational Control Centre Rail (OCCR) in Utrecht. One way to model this uncertainty is by representing the disruption length as a probabilistic distribution. A dependence model, taking the form of a joint distribution, between the disruption length and several observable influencing factors is constructed for a particular type of disruption. From the model, the conditional distribution of disruption length can be computed by conditioning the model on the observed values of the influencing factors. In this thesis, the joint distribution is constructed using the concept of copula and vines. One focus of this thesis is to study this construction when the variables involved are both discrete and continuous. We show that this can still be done, despite the more expensive parameters estimation. One value from the conditional distribution of disruption length needs to be chosen as the prediction. To investigate the effect of different choices of prediction, the model is tested in four case studies concerning a railway disruption occurring in the area of Houten, the Netherlands. The model is used together with the short-turning and the passenger flow models, developed by the Department of Transport and Planning of Delft University of Technology. Different predictions are made and the impact on the passengers is measured in terms of the total generalized travel time.
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The uncertainty of railway disruption length hinders the performance of the Operational Control Centre Rail (OCCR) in Utrecht. One way to model this uncertainty is by representing the disruption length as a probabilistic distribution. A dependence model, taking the form of a joint distribution, between the disruption length and several observable influencing factors is constructed for a particular type of disruption. From the model, the conditional distribution of disruption length can be computed by conditioning the model on the observed values of the influencing factors. In this thesis, the joint distribution is constructed using the concept of copula and vines. One focus of this thesis is to study this construction when the variables involved are both discrete and continuous. We show that this can still be done, despite the more expensive parameters estimation. One value from the conditional distribution of disruption length needs to be chosen as the prediction. To investigate the effect of different choices of prediction, the model is tested in four case studies concerning a railway disruption occurring in the area of Houten, the Netherlands. The model is used together with the short-turning and the passenger flow models, developed by the Department of Transport and Planning of Delft University of Technology. Different predictions are made and the impact on the passengers is measured in terms of the total generalized travel time.
Decreasing the uncertainty in the lengths of railway disruptions is a major help to disruption management. To assist the Dutch Operational Control Center Rail (OCCR) during disruptions, we propose the Copula Bayesian Network method to construct a disruption length prediction model. Computational efficiency and fast inference features make the method attractive for the OCCR’s real-time decision making environment. The method considers the factors influencing the length of a disruption and models the dependence between them to produce a prediction. As an illustration, a model for track circuit (TC) disruptions in the Dutch railway network is presented in this paper. Factors influencing the TC disruption length are considered and a disruption length model is constructed. We show that the resulting model’s prediction power is sound and discuss its real-life use and challenges to be tackled in practice.
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Decreasing the uncertainty in the lengths of railway disruptions is a major help to disruption management. To assist the Dutch Operational Control Center Rail (OCCR) during disruptions, we propose the Copula Bayesian Network method to construct a disruption length prediction model. Computational efficiency and fast inference features make the method attractive for the OCCR’s real-time decision making environment. The method considers the factors influencing the length of a disruption and models the dependence between them to produce a prediction. As an illustration, a model for track circuit (TC) disruptions in the Dutch railway network is presented in this paper. Factors influencing the TC disruption length are considered and a disruption length model is constructed. We show that the resulting model’s prediction power is sound and discuss its real-life use and challenges to be tackled in practice.
The use of different copula-based models to represent the joint distribution of an eight-dimensional mixed discrete and continuous problem consisting of five discrete and three continuous variables is investigated. The discussion starts with the theoretical properties of the copula-based models. Four different models are constructed for the data collected for the purpose of predicting the length of disruption caused by problems with the train detection system in the Dutch railway network and their performance is tested. The more complex models turn out to represent the data better. Nevertheless, it is shown that the simpler eight dimensional Normal copula still constitutes a statistically sound model for the data.
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The use of different copula-based models to represent the joint distribution of an eight-dimensional mixed discrete and continuous problem consisting of five discrete and three continuous variables is investigated. The discussion starts with the theoretical properties of the copula-based models. Four different models are constructed for the data collected for the purpose of predicting the length of disruption caused by problems with the train detection system in the Dutch railway network and their performance is tested. The more complex models turn out to represent the data better. Nevertheless, it is shown that the simpler eight dimensional Normal copula still constitutes a statistically sound model for the data.
The length of a disruption in a railway network is highly uncertain which complicates the incident management of traffic controllers. This paper proposes a probabilistic model based on historical data to provide the prediction of the disruption length to the Dutch Operational Control Centre Rail (OCCR). A good prediction of disruption length is believed to help the OCCR to implement an appropriate response that minimizes the impact of the disruption for the railway users. The model that is proposed in this paper is a Non-Parametric Bayesian Network (NPBN) which represents the joint distribution between variables that describe the nature of the disruption. To obtain the prediction of the disruption length, this joint distribution is conditionalized on the particular values of variables in the model that are describing the situation at hand. The NPBN allows rapid conditionalization/inference which is attractive for the real-time decision making process of the OCCR. This paper presents the first attempt to model disruption length with NPBNs. A case study concerning a specific type of railway disruption, namely malfunctioning train detection, is considered as an example of the application of the method.
...
The length of a disruption in a railway network is highly uncertain which complicates the incident management of traffic controllers. This paper proposes a probabilistic model based on historical data to provide the prediction of the disruption length to the Dutch Operational Control Centre Rail (OCCR). A good prediction of disruption length is believed to help the OCCR to implement an appropriate response that minimizes the impact of the disruption for the railway users. The model that is proposed in this paper is a Non-Parametric Bayesian Network (NPBN) which represents the joint distribution between variables that describe the nature of the disruption. To obtain the prediction of the disruption length, this joint distribution is conditionalized on the particular values of variables in the model that are describing the situation at hand. The NPBN allows rapid conditionalization/inference which is attractive for the real-time decision making process of the OCCR. This paper presents the first attempt to model disruption length with NPBNs. A case study concerning a specific type of railway disruption, namely malfunctioning train detection, is considered as an example of the application of the method.