The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Paulo Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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Stability Analysis of a DC MicroGrid for a Smart Railway Station Integrating Renewable Sources
IEEE Transactions on Control Systems Technology, 2020Co-Authors: Filipe Perez, Alessio Iovine, Gilney Damm, Lilia Galai-dol, Paulo RibeiroAbstract:A low-level distributed nonlinear controller for a DC MicroGrid integrated in a Smart Railway Station capable to recover trains' braking energy is introduced in this paper. The DC MicroGrid is composed by a number of elements: two different types of renewable energy sources (regenerative braking energy recovery from the trains and photovoltaic panels), two kinds of storages acting at different time scales (a battery and a supercapacitor), a DC load representing an aggregation of all loads in the MicroGrid, and the connection with the main AC grid. The nonlinear model of the MicroGrid is introduced, and a complete stability analysis is investigated to the purpose to meet power balance and grid voltage stability requirements. An Input-to-State Stability (ISS)-like Lyapunov function is obtained with a System-of-Systems approach, and it is utilized to develop the control laws for the converters in order to fulfill the dedicated objective each of them has. Simulation results, showing the desired grid behavior using the proposed nonlinear control laws, are introduced and compared with classical Proportional Integral (PI) linear controllers, with respect to performances and parametric robustness. The DC MicroGrid is shown to be able to operate braking energy recovery while performing load feeding and renewable energy integration and guaranteeing a proper DC voltage profile.
Filipe Perez - One of the best experts on this subject based on the ideXlab platform.
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Stability Analysis of a DC MicroGrid for a Smart Railway Station Integrating Renewable Sources
IEEE Transactions on Control Systems Technology, 2020Co-Authors: Filipe Perez, Alessio Iovine, Gilney Damm, Lilia Galai-dol, Paulo RibeiroAbstract:A low-level distributed nonlinear controller for a DC MicroGrid integrated in a Smart Railway Station capable to recover trains' braking energy is introduced in this paper. The DC MicroGrid is composed by a number of elements: two different types of renewable energy sources (regenerative braking energy recovery from the trains and photovoltaic panels), two kinds of storages acting at different time scales (a battery and a supercapacitor), a DC load representing an aggregation of all loads in the MicroGrid, and the connection with the main AC grid. The nonlinear model of the MicroGrid is introduced, and a complete stability analysis is investigated to the purpose to meet power balance and grid voltage stability requirements. An Input-to-State Stability (ISS)-like Lyapunov function is obtained with a System-of-Systems approach, and it is utilized to develop the control laws for the converters in order to fulfill the dedicated objective each of them has. Simulation results, showing the desired grid behavior using the proposed nonlinear control laws, are introduced and compared with classical Proportional Integral (PI) linear controllers, with respect to performances and parametric robustness. The DC MicroGrid is shown to be able to operate braking energy recovery while performing load feeding and renewable energy integration and guaranteeing a proper DC voltage profile.
Imre Salma - One of the best experts on this subject based on the ideXlab platform.
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properties and sources of individual particles and some chemical species in the aerosol of a metropolitan underground Railway Station
Atmospheric Environment, 2009Co-Authors: Imre Salma, Mihaly Posfai, Kristof Kovacs, E Kuzmann, Z Homonnay, Jozsef PostaAbstract:Abstract Aerosol samples in PM 10–2.0 and PM 2.0 size fractions were collected on the platform of a metropolitan underground Railway Station in central Budapest. Individual aerosol particles were studied using atomic force microscopy, scanning electron microscopy and transmission electron microscopy with energy-dispersive X-ray spectrometry and electron diffraction. The bulk aerosol samples were investigated by 57 Fe Mossbauer spectroscopy, and they were subjected to chemical speciation analysis for Cr. The particles were classified into groups of iron oxides and iron, carbonates, silicates, quartz and carbonaceous debris. Electron micrographs showed that the Fe-rich particles in the PM 2.0 size fraction typically consisted of aggregates of nano-sized hematite crystals that were randomly oriented, had round shapes and diameters of 5–15 nm. In addition to hematite, a minor fraction of the iron oxide particles also contained magnetite. In addition, the PM 2.0 -fraction particles typically had a rugged surface with layered or granular morphologies. Mossbauer spectroscopy suggested that hematite was a major Fe-bearing species in the PM 10–2.0 size fraction; its mass contribution to the Fe was 36%. Further constituents (ferrite, carbides and FeOOH) were also identified. The water soluble amounts of Cr for the underground Railway Station and city center were similar. In the PM 10–2.0 size fraction, practically all dissolved Cr had an oxidation state of three, which corresponds to ambient conditions. In the PM 2.0 size fraction, however, approximately 7% of the dissolved Cr was present as Cr(VI), which was different from that for the urban aerosol. It is suggested that the increased adverse health effects of aerosol particles in metros with respect to ambient outdoor particles is linked to the differences in the oxidation states, surface properties or morphologies.
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time resolved mass concentration composition and sources of aerosol particles in a metropolitan underground Railway Station
Atmospheric Environment, 2007Co-Authors: Imre Salma, Tamas Weidinger, Willy MaenhautAbstract:Abstract Aerosol samples were collected using a stacked filter unit (SFU) for PM10-2.0 and PM2.0 size fractions on the platform of a metropolitan underground Railway Station in downtown Budapest. Temporal variations in the PM10 mass concentration and wind speed and direction were determined with time resolutions of 30 and 4 s using a tapered-element oscillating microbalance (TEOM) and a wind monitor, respectively. Sample analysis involved gravimetry for particulate mass, and particle-induced X-ray emission spectrometry (PIXE) for elemental composition. Diurnal variation of the PM10 mass concentration exhibited two peaks, one at approximately 07:00 h and the other at approximately 17:00 h. The mean±SD PM10 mass concentration for working hours was 155±55 μg m −3 . Iron, Mn, Ni, Cu, and Cr concentrations were higher than in outdoor air by factors between 5 and 20, showing substantial enrichment compared to both the average crustal rock composition and the average outdoor aerosol composition. Iron accounted for 40% and 46% of the PM10-2.0 and PM2.0 masses, respectively, and 72% of the PM10 mass was associated with the PM10-2.0 size fraction. The aerosol composition in the metro Station (in particular the abundance of the metals mentioned above) is quite different from the average outdoor downtown composition. Mechanical wear and friction of electric conducting rails and bow sliding collectors, ordinary rails and wheels, as well as resuspension, were identified as the primary sources. Possible health implications based on comparison to various limit values and to data available for other underground Railways are discussed.
Hui Xie - One of the best experts on this subject based on the ideXlab platform.
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effect of sound on visual attention in large Railway Stations a case study of st pancras Railway Station in london
Building and Environment, 2020Co-Authors: Chang Liu, Jian Kang, Hui XieAbstract:Abstract There is a growing body of research into audio-visual interaction in architectural acoustics. The complex physical environment of a large Railway Station contributes to strong interactions between multi-sensors. This paper investigated how visual attention is shifted when sound level increases; whether the leading effect of sound on visual attention differs under the influence of pleasant, annoying, or information sounds; and whether the leading effect is affected by the correspondence between audio and visual stimuli. The study found that, as the difference between the sound levels of sound signals and background noise increased, the variation in attention rate and evaluation of the audio environment took on a parabola-shaped curve. However, in case of a pleasant sound (music), the inflection points arrived at higher sound level than that in case of an annoying noise (train noise). Pleasant sounds (music) and annoying noise were found to be more 'noticeable' than neutral sounds. In addition, sound that corresponds with visual stimuli had the most significant influence on the leading effect of sound on visual attention.
Piet Rietveld - One of the best experts on this subject based on the ideXlab platform.
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the impact of rail transport on real estate prices an empirical analysis of the dutch housing market
Urban Studies, 2011Co-Authors: Ghebreegziabiher Debrezion, Eric Pels, Piet RietveldAbstract:A hedonic pricing model is estimated to analyse the impact of Railways on house prices in terms of distance to Railway Station, frequency of Railway services and distance to the Railway line. Correcting for a wide range of other determinants of house prices we find that dwellings very close to a Station are on average about 25% more expensive than dwellings at a distance of 15 kilometres or more. A doubling of frequency leads to an increase of house values of about 2.5%, ranging from 3.5% for houses close to the Station to 1.3% for houses far away. Finally we find a negative effect of distance to Railways, probably due to noise effects. Two Railway Station references were used in the analysis: the nearest and most frequently chosen Station in the post code area. This distinction indicates that Railway Station accessibility is a more complex concept than one might think. It involves competition between Railway Stations.
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modelling the joint access mode and Railway Station choice
Transportation Research Part E-logistics and Transportation Review, 2009Co-Authors: Ghebreegziabiher Debrezion, Eric Pels, Piet RietveldAbstract:This study models the choices of Dutch Railway users. We find a steeper negative distance effect on the utility of departure Stations accessed by the non-motorized modes of walking and bicycle as compared to the motorized modes of car and public transport. Availability of parking places and bicycle standing areas have a positive effect on the choice of departure Railway Stations accessed by car and bicycle, respectively. Public transport frequency has a positive whereas travel time has a negative effect on the choice of departure Stations accessed by public transport. The derived rail service quality index (RSQI), which provides a measure of rail accessibility to all other Stations, has a significant and positive effect on the choice of departure Stations accessed by all modes. The outcome of this paper can be used to develop a comprehensive Railway accessibility indicator for neighbourhoods, for hedonic pricing studies.
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the access journey to the Railway Station and its role in passengers satisfaction with rail travel
Transport Policy, 2007Co-Authors: Moshe Givoni, Piet RietveldAbstract:This paper focuses on two lines of investigation with regard to access to Railway Stations in the Netherlands. Firstly, the profile of the access and egress modes on journeys to and from Railway Stations is analyzed. We also examine how the availability of car affects the mode choice on journeys to the Station. Secondly, the effect of passengers' perception of the Station and of the journey to the Station on the overall perception of traveling by rail is estimated. The results show that most of the passengers choose walking, bicycle and public transport to get to or from the Railway Station and that the availability of a car does not have a strong effect on the choice of access mode to the Station. The quality of the Station and the access/egress facilities was found to have an important effect on the general perception of traveling by rail.
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modelling the joint access mode and Railway Station choice
Research Papers in Economics, 2007Co-Authors: Ghebreegziabiher Debrezion, Eric Pels, Piet RietveldAbstract:This discussion paper resulted in an article in the Transportation Research E (2009). Volume 45, pages 270-283. This study models the choices of Dutch Railway users (aggregated at the 4 digit post code area) for access mode and departure Railway Stations. For each post code area a set of four access modes: car, public transport, bicycle and walking and a set three departure Railway Stations are identified. A nested logit model is estimated based on 1440 post code areas using a number of access and rail Station features. The access features include distance to the departure Station, car ownership level, public transport frequency and travel time by public transport to the departure Stations. The Station features used in the estimation include rail service quality index and supplementary facilities such as availability of parking space and bicycle standing place. Distance has a negative effect on the utility of departure Stations. A steeper effect is observed on the choice of departure Stations accessed by the non-motorized modes of walking and bicycle. Availability of parking places and bicycle standing areas have a positive effect on the choice of departure Railway Stations accessed by car and bicycle respectively. Public transport frequency has a positive whereas public transport travel time has a negative effect on the choice of departure Stations accessed by public transport. The rail service quality index of a Station has a significant and positive effect on the choice of departure Stations accessed by all modes.
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how do people get to the Railway Station the dutch experience
Transportation Planning and Technology, 2000Co-Authors: M J N Keijer, Piet RietveldAbstract:The quality of transport networks does not only depend on the quality of the individual links and nodes, but also on the way these nodes and links function in the context of multimodal networks. In the present paper we focus on multimodal trips where the Railways are the main transport mode. We discuss detour and frequency problems related to multimodal transport chains. Local accessibility of Railway Stations is an important determinant of Railway use in the Netherlands. We find that the propensity to make use of rail services by people living in the ring between 500 to 1000 meters from a Railway Station is about 20% lower than of people living at most 500 meters away from Railway Stations. At distances between 1.0 and 3.5 km the distance decay effect is about 30%, and above this distance it may reach values up to 50%. Non‐motorized transport modes are dominant at both the home‐end and the activity‐end. A rather unique feature of the home‐end access mode is the high share of the bicycle. More than one ou...
