References of "Viti, Francesco 50003272"
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See detailEstimating Urban Road Traffic States Using Mobile Network Signaling Data
Derrmann, Thierry UL; Frank, Raphaël UL; Viti, Francesco UL et al

in Abstract book of the 20th International Conference on Intelligent Transportation Systems (2017, October)

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used ... [more ▼]

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used in analyses, but also handovers between different locations that reflect mobility. In this work, we investigate if handovers can be used as a proxy metric for flows in the underlying road network, especially in urban environments. More precisely, we show that characteristic profiles of handovers within and between clusters of mobile network cells exist. We base these profiles on models from road traffic flow theory, and show that they can be used for traffic state estimation using floating-car data as ground truth. The presented model can be beneficial in areas with good mobile network coverage but low road traffic counting infrastructure, e.g. in developing countries, but also serve as an additional predictor for existing traffic state monitoring systems. [less ▲]

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See detailEffectiveness of the Two-Step Dynamic Demand Estimation model on large networks
Cantelmo, Guido UL; Viti, Francesco UL; Derrmann, Thierry UL

in Abstract book of 2017 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS) (2017, June 28)

In this paper, the authors present a Two-Step approach that sequentially adjusts generation and distribution values of the (dynamic) OD matrix. While the proposed methodology already provided excellent ... [more ▼]

In this paper, the authors present a Two-Step approach that sequentially adjusts generation and distribution values of the (dynamic) OD matrix. While the proposed methodology already provided excellent results for updating demand flows on a motorway, the aim of this paper is to validate this conclusion on a real network: Luxembourg City. This network represents the typical middle-sized European city in terms of network dimension. Moreover, Luxembourg City has the typical structure of a metropolitan area, composed of a city centre, ring, and suburb areas. An innovative element of this paper is to use mobile network data to create a time-dependent profile of the generated demand inside and outside the ring. To support the claim that the model is ready for practical implementation, it is interfaced with PTV Visum, one of the most widely adopted software tools for traffic analysis. Results of these experiments provide a solid empirical ground in order to further develop this model and to understand if its assumptions hold for urban scenarios. [less ▲]

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See detailHow Mobile Phone Handovers reflect Urban Mobility: A Simulation Study
Derrmann, Thierry UL; Frank, Raphaël UL; Engel, Thomas UL et al

in Proceedings of the 5th IEEE Conference on Models and Technologies for Intelligent Transportation Systems. (2017, June 26)

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See detailOn the consistency between commuting satisfaction and traveling utility: the case of the University of Luxembourg
Sprumont, François UL; Astegiano, Paola; Viti, Francesco UL

in European Journal of Transport and Infrastructure Research (2017), 17(2), 248-262

According to random utility theory, there is no clear distinction between the utility inferred from observed choices (decision utility), the experienced outcome of decision makers’ (experienced utility ... [more ▼]

According to random utility theory, there is no clear distinction between the utility inferred from observed choices (decision utility), the experienced outcome of decision makers’ (experienced utility) or their retrospective evaluation (remembered utility). While empirical experiments have shown that decision utility and remembered utility do not perfectly coincide, little is known regarding the magnitude of this discrepancy, especially in the transport field. Using a cross-sectional travel survey, the objective of this paper is to quantify the relationship between commuters’ stated choice satisfaction (a proxy for remembered utility) and the Logsum function of the utility of all available modes of transport (decision utility). This is of tremendous importance, as implemented transport policy measures, which aim to increase the overall decision makers’ utility, may have low impact on their satisfaction level and thus be ineffective. Results indicate that the utility Logsum is associated with respondents’ commuting satisfaction. However, context specificities have an important impact on this association. [less ▲]

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See detailUsage of Smartphone Data to Derive an Indicator for Collaborative Mobility between Individuals
Toader, Bogdan UL; Sprumont, François UL; Faye, Sébastien UL et al

in ISPRS International Journal of Geo-Information (2017), 6(3), 62

The potential of geospatial big data has been drawing attention for a few years. Despite the larger and larger market penetration of portable technologies (nomadic and wearable devices like smartphones ... [more ▼]

The potential of geospatial big data has been drawing attention for a few years. Despite the larger and larger market penetration of portable technologies (nomadic and wearable devices like smartphones and smartwatches), their opportunities for travel behavior analysis are still relatively unexplored. The main objective of our study is to extract the human mobility patterns from GPS traces in order to derive an indicator for enhancing Collaborative Mobility (CM) between individuals. The first step, extracting activity duration and location, is done using state-of-the-art automated recognition tools. Sensors data are used to reconstruct individual’s activity location and duration across time. For constructing the indicator, in a second step, we defined different variables and methods for specific case studies. Smartphone sensor data are being collected from a limited number of individuals and for one week. These data are used to evaluate the proposed indicator. Based on the value of the indicator, we analyzed the potential for identifying CM among groups of users, such as sharing traveling resources (e.g., carpooling, ridesharing, parking sharing) and time (rescheduling and reordering activities). [less ▲]

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See detailA New Modelling Framework over Temporal Graphs for Collaborative Mobility Recommendation Systems
Toader, Bogdan UL; Moawad, Assaad UL; Fouquet, François UL et al

Scientific Conference (2017)

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data ... [more ▼]

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data science as an enabler for the implementation of large scale transportation sharing solutions. In particular, the next generation of Intelligent Transportation Systems (ITS) requires the combination of artificial intelligence and discrete simulations when exploring the effects of whatif decisions in complex scenarios with millions of users. In this paper, we address this challenge by presenting an innovative data modelling framework that can be used for ITS related problems. We demonstrate that the use of graphs and time series in multi-dimensional data models can satisfy the requirements of descriptive and predictive analytics in real-world case studies with massive amounts of continuously changing data. The features of the framework are explained in a case study of a complex collaborative mobility system that combines carpooling, carsharing and shared parking. The performance of the framework is tested with a large-scale dataset, performing machine learning tasks and interactive realtime data visualization. The outcome is a fast, efficient and complete architecture that can be easily deployed, tested and used for research as well in an industrial environment. [less ▲]

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See detailA real-time holding decision rule accounting for passenger travel cost
Laskaris, Georgios UL; Cats, Oded; Jenelius, Erik et al

Scientific Conference (2016, November 04)

Holding has been extensively investigated as a strategy to mitigate the inherently stochastic nature of public transport operations. Holding focuses on either regulating vehicle headways using a rule ... [more ▼]

Holding has been extensively investigated as a strategy to mitigate the inherently stochastic nature of public transport operations. Holding focuses on either regulating vehicle headways using a rule-based approach or minimizing passenger travel cost by employing optimization models. This paper introduces a holding decision rule that explicitly addresses passenger travel cost. The decision to hold relies on the passenger demand distribution along the line. The passenger cost holding rule is tested using simulation for a high frequency bus line in Stockholm, Sweden and is compared with a nocontrol scheme and the currently used headway-based strategy. The results indicate that the new decision rule results in relatively minor reductions of passenger cost compared to the currently adopted strategy, and that it allocates the greatest share of holding time at the beginning of the route. [less ▲]

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See detailA Survey of Cooperative ITS for Next Generation Public Transport Systems
Seredynski, Marcin; Viti, Francesco UL

in Intelligent Transportation Systems (ITSC), 2016 IEEE 19th International Conference on (2016, November)

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See detailA network-wide assessment of local signal control policies’ performance in practical implementations
Cantelmo, Guido UL; Viti, Francesco UL; Rinaldi, Marco UL

in Intelligent Transportation Systems (ITSC), 2016 IEEE 19th International Conference on (2016, November)

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See detailCross-border activity-travel patterns: the Luxembourg residents perspective
Sprumont, François UL; Piroth, Isabelle UL; Viti, Francesco UL

Scientific Conference (2016, October 07)

Despite its small size (2586 km2), the Grand-duchy of Luxembourg is a strong economic locomotive. Indeed, among the 380 000 available jobs in the country, 44% are occupied by cross-border workers from ... [more ▼]

Despite its small size (2586 km2), the Grand-duchy of Luxembourg is a strong economic locomotive. Indeed, among the 380 000 available jobs in the country, 44% are occupied by cross-border workers from France, Belgium and Germany. While the commuting behavior and the activity chains of the cross-border workers have been largely studied (Carpentier, 2012, Drevon et al., 2013, Gerber, 2012) this is not the case for the population living in Luxembourg. This scientific contribution aims at analyzing the daily activity chains of resident population. Do residents perform all their activities in Luxembourg? If not, in which country do they go and for which type of activity? Due to the small size of the country and plausible attraction for surrounding countries (linked to familial reasons, nationality, past residential place of residence, differentials in prices etc.) the people living in Luxembourg might conduct some activities in Belgium, France or Germany. Between June and July 2015, a multi-day survey has been implemented on 52 staff members of the University of Luxembourg working, at that time, at Walferdange campus. These individuals provided information regarding their daily activities (activity duration and location, activity type) and their travel behavior (travelling time and mode) for two weeks. Among the respondents, 35 participants are living in Luxembourg and provided information for 490 days and 1850 activities in total. The studied population is interesting in many aspects. First of all, the individuals were working in Walferdange, a city located 8 km north of Luxembourg-city, so a central geographic position. Second, this is a high-qualified and international population. Actually, the education level of the respondents is high (45% have a PhD degree, 37% a master degree) and many of them moved to Luxembourg because of the attractive labour market. Third, the income of the surveyed population is higher than the average national salary. With its limited area, one would think that individuals living in Luxembourg would cross the borders quite often for shopping, leisure activities...However, Luxembourg has abundant and various services (shopping malls, leisure and cultural places ...). Indeed close to 30% of the respondents had all their activities in Luxembourg and out of the 1850 total activities, only 130 had been done in a neighboring country. But on the other hand, one fourth of the respondents had done 75% of total activities outside Luxembourg. In a way to better understand the mobility behavior of resident population, a detailed activity chain analysis will be presented. This will be completed by a spatial analysis of the activities, in order to examine the effects of the borders on non-work related activities. Finally, different activity behaviors will be identified through a multivariate analysis. The results of this explorative analysis will be compared to the abundant literature regarding the behavior of the cross-borders workers. [less ▲]

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See detailTowards Optimised Large Scale Deployments of Electric Bus Systems with On-Route Charging
Seredynski, Marcin; Khadraoui, Djamel; Viti, Francesco UL

Scientific Conference (2016, October)

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See detailConsidering activity pattern to achieve a more sustainable commuting behavior
Sprumont, François UL; Caruso, Geoffrey UL; Viti, Francesco UL et al

Scientific Conference (2016, September 19)

While commuting allows workers to take part to the economy, this specific trip represents a non-negligible share of the total trips undertaken by individuals. Because of the repetitive pattern both in ... [more ▼]

While commuting allows workers to take part to the economy, this specific trip represents a non-negligible share of the total trips undertaken by individuals. Because of the repetitive pattern both in time and space of the home-to-work trip, different transport policies can be implemented in order to reduce some of its negative impacts. Travel Demand Management (TDM) measures aim at reducing the transport demand or inducing a modal shift towards active or public transport modes. Too often, these strategies, by focusing narrowly on the home-to-work trip, do not take into account the complexity of the individuals’ daily activity chain. Indeed, the complexity of the activity pattern might impede some workers to use public or active modes for the commuting trip despite, for instance, a very short home-to-work distance. Results of a Structural Equation Modelling (SEM) approach indicates that, for working days, socio-demographic variables affect more car use than activity-chain complexity. Thus, the proposed TDM measures aiming at decreasing car use for commuting takes into account the daily activity behavior but also suggest ways to deal with individual’s characteristics [less ▲]

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See detailAnalyzing the correlation between commuting satisfaction and travelling utility
Sprumont, François UL; Astegiano, Paola; Viti, Francesco UL

Scientific Conference (2016, July 13)

The interest for travel satisfaction has rapidly grown during the past two decades. Since the development of Discrete Choice Theory, doing a trip was mostly described as a pure derived activity without ... [more ▼]

The interest for travel satisfaction has rapidly grown during the past two decades. Since the development of Discrete Choice Theory, doing a trip was mostly described as a pure derived activity without utility per se but nowadays many scholars have demonstrated that individuals might be satisfied in performing the trip itself. However, little is still known on the relation between the travelling utility and the stated satisfaction for a specific trip. The objective of this paper is to analyse the relation between the stated commuting satisfaction and the utility of the associated trip thanks to the Logsum function, which is often used to represent the aggregated utility of a set of travel alternatives. The results of a travel survey implemented at the University of Luxembourg in 2012, show that the utility function, expressed through its Logsum, is positively correlated with the stated commuting satisfaction. While the Logsum function of the travelling utility might, to some extent, approximate the travelling satisfaction, some variations in the correlation magnitude, due to context particularities and socio-demographic attributes, are observed and discussed in this study. [less ▲]

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See detailAn Extended Cooperative Adaptive Cruise Control (CACC) Algorithm for Efficient Energy Consumption & Traffic Density Formulation
Bayar, Bilgehan; Sajadi Alamdari, Seyed Amin UL; Viti, Francesco UL et al

in Traffic Flow Theory and Characteristics Committee (AHB45) 2016 Summer Meeting, Sydney, Australia, 2016 (2016, July 02)

Electric transportation, one of the most promising technologies of the century, can contribute to a greener environment as it is emission-free and sustainable. Although this technology promises a clean ... [more ▼]

Electric transportation, one of the most promising technologies of the century, can contribute to a greener environment as it is emission-free and sustainable. Although this technology promises a clean transportation style, it also has some drawbacks. One of the most significant one is cruising range, which needs to be addressed sustainably. The most eco-friendly solution is decreasing energy consumption by addressing driving behaviour. This can be achieved by taking the advantage of implementing an advancing vehicle automation technology which controls vehicles using a driver-assistance system such as Eco-Cruise Control (Eco-CC). Variety of systems already exist in the literature and a little known advanced version Eco-Adaptive Cruise Control (Eco-ACC) systems are developed as well. The next step of the vehicle automation is vehicle cooperation and information sharing, so-called Cooperative Adaptive Cruise Control (CACC). It is already developed and tested by various researcher. However, the largest deal of existing studies focus on assessing the performance in terms of safety, possible contributions to the energy consumption is not taken into account. This study covers the extension of Cooperative Adaptive Cruise Control systems while aiming to provide an energy efficient extended control algorithm to increase the energy efficiency and battery usage for electric vehicles. An energy efficient control algorithm is aimed to be derived to decrease the consumption of the vehicle. Cruising velocities and vehicle positions are received from the leading vehicles and accordingly traction force is adjusted to achieve efficient energy consumption. By providing vehicle to vehicle (V2V) communication tighter spacing gaps, lower time headway, are aimed to obtain while traffic disturbances are damped, whereas in the cases ACC applications amplify the disturbance. Traffic density formula is introduced by using V2V communication which might be useful for ADAS and ITS framework. As a result, increase in traffic stability, density, and reduction in the total energy consumption is expected. Moreover, possible reductions in air drag with tighter spacing gaps may lead reduction in energy consumption. For the energy calculations and the validation of the proposed method, vehicle dynamics and energy consumption of an electric car is formulated, which has completely different characteristics and limitations than combustion engine cars. Hence the study aims to provide additional understanding of behaviour of a fleet of CACC-equipped electric vehicles. Even though the proposed control algorithm is developed for Electric Vehicles, it can be extended to other vehicle types based on their energy consumption characteristics and vehicle dynamics. [less ▲]

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See detailA dynamic route swapping and control algorithm that maximises network capacity accounting for node constraints and blocking back
Viti, Francesco UL; Huang, Wei; Smith, Mike

Scientific Conference (2016, July)

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See detailImpact of Different Spacing Policies for Adaptive Cruise Control on Traffic and Energy Consumption of Electric Vehicles
Bayar, Bilgehan; Sajadi Alamdari, Seyed Amin UL; Viti, Francesco UL et al

in 24th Mediterranean Conference on Control and Automation (MED), Athens, Greece, 2016 (2016, June 23)

This paper assesses the impact of different spacing policies for Adaptive Cruise Control (ACC) systems on traffic and environment. The largest deal of existing studies focus on assessing the performance ... [more ▼]

This paper assesses the impact of different spacing policies for Adaptive Cruise Control (ACC) systems on traffic and environment. The largest deal of existing studies focus on assessing the performance in terms of safety, while only few deal with the effect of ACC on the traffic flow and the environment. In particular, very little is know on traffic stability and energy consumption. In this study, the vehicles equipped with ACC are modelled and controlled by two different spacing policies. Besides, Human Driving Behavior (HDB) is modelled by using Gipps model for comparison and for simulating different penetration rates. As distinguished from other studies, vehicle dynamics and energy consumption of an electric car is formulated, which has completely different characteristics and limitations than combustion engine cars. Hence the study aims at providing additional understanding of how ACC-equipped electric vehicles will behave in dense traffic conditions. HDB and ACC vehicles are placed in a roundabout at different penetration rates. String stability and energy consumption are investigated by giving a shock wave to a stable traffic condition. It is found that ACC with quadratic spacing policy has significantly positive effects on string stability and energy consumption. [less ▲]

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See detailEstimating speed profiles from aerial vision - A comparison of regression based sampling techniques
Freis, Sebastian; Olivares Mendez, Miguel Angel UL; Viti, Francesco UL

in Proceedings of the IEEE 24th Mediterranean Conference on Control and Automation (2016, June)

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See detailNetwork observability information maximization through ad-hoc route enumeration approaches
Rinaldi, Marco UL; Corman, Francesco; Viti, Francesco UL

Scientific Conference (2016, June)

Detailed reference viewed: 28 (1 UL)