Search results for " transportation"
showing 10 items of 511 documents
L∞ estimates in optimal mass transportation
2016
We show that in any complete metric space the probability measures μ with compact and connected support are the ones having the property that the optimal transportation distance to any other probability measure ν living on the support of μ is bounded below by a positive function of the L∞ transportation distance between μ and ν. The function giving the lower bound depends only on the lower bound of the μ-measures of balls centered at the support of μ and on the cost function used in the optimal transport. We obtain an essentially sharp form of this function. In the case of strictly convex cost functions we show that a similar estimate holds on the level of optimal transport plans if and onl…
The collaborative consistent vehicle routing problem with workload balance
2021
Abstract The rising competition in the logistics sector forces companies to be more economically efficient. One of the major sources of inefficiency is the incomplete usage of available resources, such as vehicles’ capacities. Mechanism that allow to better exploit such resources by enabling carrier collaborations are on the rise. Our study examines a centrally organized multi-period collaborative vehicle routing problem, where carriers can exchange customers who have to be serviced on a regular basis. Collaborations, where carriers serve frequent customers, are supposed to face the problem of (i) time consistency in terms of visiting time, and of (ii) service consistency. The latter ensure…
Branch-and-Cut-and-Price for the Vehicle Routing Problem with Time Windows and Convex Node Costs
2019
Two critical yet frequently conflicting objectives for logistics and transportation service companies are improving customer satisfaction and reducing transportation cost. In particular, given a network of customer requests with preferred service times, it is very challenging to find vehicle routes and service schedules simultaneously that respect all operating constraints and minimize the total transportation and customers’ inconvenience costs. In this paper, we introduce the vehicle routing problem with time windows and convex node costs (VRPTW-CNC), in which we model each customer’s inconvenience cost as a convex function of the service start time at that customer. The VRPTW-CNC combine…
Multi-Connectivity Management for 5G V2X Communication
2019
With the advent of automated driving functions the need for cooperation among vehicles becomes increasingly necessary. The availability of high quality connectivity is an important factor for successful and uninterrupted cooperative and autonomous services. Flexible selection of available connectivity options, increases the probabilities to achieve and maintain the required Quality of Service (QoS). Future vehicles will support multiple 5G communication interfaces e.g., cellular (Uu), sidelink (PC5). A 5G RAN-based solution is proposed in this paper to dynamically select and change the communication interface that is suitable for a V2X service, considering radio and road conditions. The com…
Understanding the Key Factors of Shared Mobility Services: Palermo as a Case Study
2020
The potential success of shared mobility services in the urban area strongly depends on careful tariff planning, adequate sizing of the fleet and efficient integrated public transport system, as well as on the application of policies in favor of sustainable modes of transport. The balance between earnings and expenses is not always an easy target for the companies in those cities where these services are not well-rooted in the citizens’ mobility habits. Often only large operators in the sector can continue to offer a service generating profit. However, several factors can determine the success or the failure of shared mobility services. The objective of this study is to identify, thanks to …
Techno-economical inspection of high-speed Internet connection for trains
2008
Some attractive service scenarios for Railways' Intelligent Transport Systems (RITS) in three different user segments, that is, passengers, freight companies and train operator's in-house customers, are presented. The case study covers the analysis of customer needs and techno-economic evaluations. The analysis indicates that Flash-OFDM technology provides promising pre-stage solution for the train connections in Finland. Also, the WiMAX-based high-speed Internet access for passengers may be profitable in the most heavily operated railway leg in Finland. The sensitivity analysis shows that the most crucial parameters for the case are `User Share', `Average Revenue per User' and `WiMAX Cell …
Forecasting noise levels by means of neural networks for assessing urban traffic policies
2005
Within the assessment of the sustainability of plans and actions concerning the built environment, the transportation sector plays an increasing role, due to its importance in the economic and social life of countries. As that, the analysis of the sustainability concerning the transportation sector is now often embodied into the so called Strategic Environmental Analyses (SEA), that should provide local administrators with easy criteria for ranking the environmental suitability of designing policies, and that would seem to encounter the needed features for a correct evaluation of the urban masterplan. The urban noise forecast is very useful for local administrations, which have presently to…
Assessing the Ecological Footprint of an Urban Transportation System
2003
The ecological footprint methodology is here applied to the urban transport system of the Italian town of Palermo (Sicily). By only using the current running fleet, a synthetic indicator represented by the "equivalent bio-productive" land, corresponding to the actual transport configuration, will be built up. This indicator can be usefully adopted for ranking various options in the urban context referring, for example, to different arrangements of the transportation demand between private and public means. This could allow local administrations to environmentally hierarchizing alternative plans concerning the urban transportation
A Network Tomography Approach for Traffic Monitoring in Smart Cities
2018
Traffic monitoring is a key enabler for several planning and management activities of a Smart City. However, traditional techniques are often not cost efficient, flexible, and scalable. This paper proposes an approach to traffic monitoring that does not rely on probe vehicles, nor requires vehicle localization through GPS. Conversely, it exploits just a limited number of cameras placed at road intersections to measure car end-to-end traveling times. We model the problem within the theoretical framework of network tomography, in order to infer the traveling times of all individual road segments in the road network. We specifically deal with the potential presence of noisy measurements, and t…
Automatic Generation of Custom Tourist Routes
2019
In this paper we present a new tool for the automatic generation of custom tourist routes. Starting from the user preferences (place to visit, starting and ending points, available time, favourite types of attractions) our system is able to extract information from the Web and to suggest a custom route to the user. Our system is based only onto online information, which is dynamically extracted at the query time, so that it can work for every location in the world, with no restrictions. Furthermore, our method does not require any user intervention, unless the input parameters. Our system is also able to give to the users supplementary information about the route stops, as a photo slideshow…