A Decision Support Tool for Energy-Optimising Railway Timetables Based on Behavioural Data

Energy-efficient train operation can reduce operating costsand contribute to a reduction in CO2 emissions. To utilise the fullpotential of energy-efficient driving, energy-efficient timetabling is crucial.To address this problem, we propose a decision support tool togive timetable planners insight into energy consumption for a giventimetable. The decision support tool uses a recommendation based onquadratic optimisation of a given timetable. Differently to previous work,the optimisation uses actual data from the train operation, which is preprocessed by data reduction, outlier detection, and second-degree regression modelling. With this approach, our results show that the optimisedtimetables can save up to 33.07% energy on a single section and up to6.23% for a complete timetable. Solutions are computed in less than amicrosecond

On train track splitting sequences

We show that the subsurface projection of a train track splitting sequence is an unparameterized quasi-geodesic in the curve complex of the subsurface. For the proof we introduce induced tracks, efficient position, and wide curves. This result is an important step in the proof that the disk complex is Gromov hyperbolic. As another application we show that train track sliding and splitting sequences give quasi-geodesics in the train track graph, generalizing a result of Hamenstaedt [Invent. Math.].Comment: 40 pages, 12 figure

Development of an efficient finite element model for the dynamic analysis of the train-bridge interaction

The design of high-speed railway bridges comprises a set of demands, from safety and serviceability aspects, to new types of equipment and construction solutions. In order to perform an accurate and realistic evaluation of the corresponding dynamic behavior, adequate analysis tools that take into account the complexity of the train-bridge system are required. These computational tools must be based on efficient algorithms to allow for the completion of detailed dynamic analyses in a reasonable amount of time. The classical methods of analysis may be unsatisfactory in the evaluation of the dynamic effects of the train-bridge system and fully assessment of the structural safety, track safety and passenger comfort. A direct and versatile technique for the simulation of the train-bridge interaction was implemented in the FEMIX code, which is a general purpose finite element computer program. The presented case study is an application of the proposed formulation, which proved to be very accurate and efficient

Dynamic analysis of the train-bridge interaction: an accurate and efficient numerical method

The dynamic behavior of railway bridges carrying high-speed trains can be analyzed with or without the consideration of the vehicle's own structure. However, due to the amount of kinetic energy carried at high speeds, the train may interact significantly with the bridge, especially when resonance occurs. Equally important is the riding comfort and the stability of the track and train cars, which are usually the most critical limit states in the design of this type of structures. With the aim of studying this problem a computer code was developed, being the interaction between the bridge and the train implemented by means of contact conditions between each train wheel (nodal point) and the structure (point inside a finite element). The treatment of the interaction between a train wheel and a point on the surface of a finite element is directly and efficiently implemented by means of an extended stiffness matrix, which includes stiffness, flexibility and additional terms that stem from the compatibility equations between the displacements of the vehicle and the bridge. This methodology was applied to the study of the dynamic behavior of a bowstring arch bridge and proved to be very accurate and efficien

Using Volunteers in Naturalization Workshops

Volunteers are a critical component of efficient naturalization service delivery, especially in group processing workshops, which the New Americans Campaign (NAC) promotes. This toolkit provides recommendations for organizations on how to recruit, train, retain, and effectively use volunteers at group processing workshops