411 research outputs found
A Deep Learning-Based Approach for Train Arrival Time Prediction
Level crossings have a function to let the traffic cross the railroad from one side to the other. In the Netherlands, 2300 level crossings are spread out over the country, playing a significant role in daily traffic. Currently, there isn’t an accurate estimation of the arrival time of trains at level crossings while it plays an important role in traffic flow management in intelligent transport systems. This paper presents a state-of-the-art deep learning model for predicting the arrival time of trains at level crossings using spatial and temporal aspects, external attributes, and multi-task learning. The spatial and temporal aspects incorporate geographical and historical travel data and the attributes provide specific information about a train route. Using multi-task learning all the information is combined and an arrival time prediction is made both for the entire route as for sub-parts of that route. Experimental results show that on average, the error is only 281 s with an average trip time of one hour. The model is able to accurately predict the arrival time at level crossings for various time steps in advance. The source code is available at https://github.com/basbuijse/train-arrival-time-estimator.</p
The scaling properties of exchange and correlation holes of the valence shell of second row atoms
We study the exchange and correlation hole of the valence shell of second row
atoms using variational Monte Carlo techniques, especially correlated
estimates, and norm-conserving pseudopotentials. The well-known scaling of the
valence shell provides a tool to probe the behavior of exchange and correlation
as a functional of the density and thus test models of density functional
theory. The exchange hole shows an interesting competition between two scaling
forms -- one caused by self-interaction and another that is approximately
invariant under particle number, related to the known invariance of exchange
under uniform scaling to high density and constant particle number. The
correlation hole shows a scaling trend that is marked by the finite size of the
atom relative to the radius of the hole. Both trends are well captured in the
main by the Perdew-Burke-Ernzerhof generalized-gradient approximation model for
the exchange-correlation hole and energy.Comment: 18 pages, 8 figure
Hydromorphological frameworks: emerging trajectories
This paper forms a postscript to a Special Issue that reports on research funded through the European Union’s FP7 programme under Grant Agreement No. 282656 (REFORM)
Integrated planning framework for successful river restoration projects: upscaling lessons learnt from European case studies
Despite considerable investment in river restoration projects, there is still limited information on the efficacy and success of river restoration activities. One of the main reasons is poor or improper project design, resulting in common problems such as: not addressing the root cause of habitat degradation; not establishing reference conditions, benchmarks and not defining endpoints against which to measure success; inappropriate uses of common restoration techniques because of lack of pre-planning; and inadequate monitoring or appraisal of restoration projects. In this paper peer-reviewed and grey literature and a large database of existing case studies were reviewed to identify the prevailing challenges river managers face when planning and developing river restoration projects. To overcome these current challe nges an integrated project planning framework has been developed that incorporates adaptive management and project management techniques. It encapsulates key concepts and decision support tools to advance the existing sequence of project identification, project formulation, project implementation and post-project monitoring to incorporate multidisciplinary decision making to meet specific environmental and socio-economic objectives. The proposed river restoration project planning framework is adaptable and can therefore be applied to any project development scenario locally, regionally or internationally
Vissen KRW
Voor de beoordeling van de ecologische toestand van rivieren moeten volgens de KRW verschillende biologische en chemische parameters worden beoordeeld met behulp van maatlatten. De bijvangst van beroepsmatige fuikvissers is een vorm van monitoring, die zeer van belang i
Riviervis terug in de rivieren?
Inventarisatie van vissoorten in de Nederlandse rivieren, mede op basis van registratie door beroepsvissers. Tevens een analyse van de habitatseisen, die het herstel van de visstand kunnen bevordere
Physical signatures of discontinuities of the time-dependent exchange-correlation potential
The exact exchange-correlation (XC) potential in time-dependent
density-functional theory (TDDFT) is known to develop steps and discontinuities
upon change of the particle number in spatially confined regions or isolated
subsystems. We demonstrate that the self-interaction corrected adiabatic
local-density approximation for the XC potential has this property, using the
example of electron loss of a model quantum well system. We then study the
influence of the XC potential discontinuity in a real-time simulation of a
dissociation process of an asymmetric double quantum well system, and show that
it dramatically affects the population of the resulting isolated single quantum
wells. This indicates the importance of a proper account of the discontinuities
in TDDFT descriptions of ionization, dissociation or charge transfer processes.Comment: 17 pages, 6 figure
Linking environmental flows to sediment dynamics
© 2017 The Authors. This is a policy discussion paper aimed at addressing possible alternative approaches for environmental flows (e- Flows) assessment and identification within the context of best strategies for fluvial restoration. We focus on dammed rivers in Mediterranean regions. Fluvial species and their ecological integrity are the result of their evolutionary adaptation to river habitats. Flowingwater is themain driver for development and maintenance of these habitats,which is why e-Flows are needed where societal demands are depleting water resources. Fluvial habitats are also shaped by the combined interaction ofwater, sediments,woody/organicmaterial, and riparian vegetation.Water abstraction, flowregulation by dams, gravel pits or siltation by fine sediments eroded fromhillslopes are pressures that can disturb interactions among water, sediments, and other constituents that create the habitats needed by fluvial communities. Present e-Flow design criteria are based only on water flow requirements. Here we argue that sediment dynamics need to be considered when specifying instream flows, thereby expanding the environmental objectives and definition of e-Flows to include sediments (extended e-Flows). To this aim, a hydromorphological framework for e-Flows assessment and identification of best strategies for fluvial restoration, including the context of rivers regulated by large dams, is presented
- …