Search results for "transportation"
showing 10 items of 860 documents
Optimal mass transportation for costs given by Finsler distances via p-Laplacian approximations
2016
Abstract In this paper we approximate a Kantorovich potential and a transport density for the mass transport problem of two measures (with the transport cost given by a Finsler distance), by taking limits, as p goes to infinity, to a family of variational problems of p-Laplacian type. We characterize the Euler–Lagrange equation associated to the variational Kantorovich problem. We also obtain different characterizations of the Kantorovich potentials and a Benamou–Brenier formula for the transport problem.
Personal Exposure to Ultrafine Particles According to Different Environments and Modes of Transport in Schoolchildren: Results from a Spanish Cohort …
2017
Background Combustion, especially in diesel engines, emits a complex mixture of gases and particles that could be harmful for the respiratory and cardiovascular systems. Daily personal exposure to the smallest particulate matter (less than 0.1 µm and usually called nanoparticles or ultrafine particles – UFP) has been studied to a lesser extent compared to coarser particles. In this study we aim to assess personal exposure to UFP in different environments and transport modes among schoolchildren from a Spanish birth-cohort in the province of Valencia. Methods The study population consisted of 114 children aged 10-11 years. For each of them, personal exposure to UFP was measured continuously …
Vessel noise pollution as a human threat to fish: assessment of the stress response in gilthead sea bream (Sparus aurata, Linnaeus 1758)
2016
This study examined the effects of boat noise pollution on the stress indices of gilthead sea bream (Sparus aurata, Linnaeus 1758). To assess the stress response in these fish, biometric values and plasma parameters such as ACTH, cortisol, glucose, lactate, haematocrit, Hsp70, total protein, cholesterol, triglycerides and osmolarity were analysed. After acclimatization of the animals, the experiment was carried out in a tank fitted with underwater speakers where the fish were exposed to sound treatments (in duplicate) consisting of: 10 days of no sound (control treatment; the animals were only exposed to the experimental tank’s background noise) and 10 days of noise derived from original re…
Are alternative food networks winning strategies to increase organic SMEs profitability? Evidence from a case study
2020
The aim of this study was to understand how and how much alternative food networks (AFNs) contribute to increasing the profitability of the organic SMEs, compared to traditional organic sales channels. For this purpose, an economic analysis and an in-depth interview were carried out in a case study located in the Sicilian northern coast. Findings showed a clear convenience of the participation to alternative food networks compared to the case in which all farm production was conferred to traditional sales channels, highlighting an increase both of farm profit (+76.9%) and net income (+72.1%). However, the in-depth interview revealed that AFNs are a mean, not only to have economic benefits, …
Seaport competitiveness research: the past, present and future
2019
This study presents a review of articles with a focus on seaport competitiveness from the maritime literature. We investigated how port competitiveness research has evolved during the last two decades using bibliometric citation analysis tools and techniques. Bibliography data, collected from the ISI Web of Science database, consisted of 267 research papers by 465 authors in 117 journals. Based on citation analysis, we identified the key universities, journals and articles and their impact on port competitiveness research. Also, seven key research streams with few sub-streams were revealed as a result of a mixed co-citation and in-depth content analysis of the most cited articles. A bibliom…
A spatially explicit risk assessment approach: Cetaceans and marine traffic in the Pelagos Sanctuary (Mediterranean Sea).
2017
15 páginas, 5 figuras, 2 tablas.-- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Communication cost of channel estimation interpolation for group-based vehicular communications in cellular networks
2020
Las comunicaciones inalámbricas para aplicaciones vehiculares en sistemas celulares de quinta generación (5G) deben ser de baja latencia y alta fiabilidad. Entre otros factores, la cantidad de información de control que debe intercambiarse entre cada vehículo y la estación base puede penalizar la latencia de la comunicación. Varios casos de uso vehicular 5G implican comunicaciones dentro de grupos de vehículos, por ejemplo el pelotón de vehículos. Este trabajo se centra en explotar la estructura y características de este servicio vehicular particular basado en grupos para disminuir el intercambio de información de control relacionado con la etapa de estimación del canal necesaria para las c…
Traffic data acquirement by unmanned aerial vehicle
2017
This paper presents a methodology aimed to acquire traffic flow data through the employment of unmanned aerial vehicles (UAVs). The study is focused on the determination of driving behavior parameters of road users and on the reconstruction of traffic flow Origin/Destination matrix. The methodology integrates UAV flights with video image processing technique, and the capability of geographic information systems, to represent spatiotemporal phenomena. In particular, analyzing different intersections, the attention of the authors is focused on users’ gap acceptance in a naturalistic drivers’ behavior condition (drivers are not influenced by the presence of instruments and operators on the roa…
Haptic and Visual Feedback Assistance for Dual-Arm Robot Teleoperation in Surface Conditioning Tasks
2020
Contact driven tasks, such as surface conditioning operations (wiping, polishing, sanding, etc.), are difficult to program in advance to be performed autonomously by a robotic system, specially when the objects involved are moving. In many applications, human-robot physical interaction can be used for the teaching, specially in learning from demonstrations frameworks, but this solution is not always available. Robot teleoperation is very useful when user and robot cannot share the same workspace due to hazardous environments, inaccessible locations, or because of ergonomic issues. In this sense, this article introduces a novel dual-arm teleoperation architecture with haptic and visual feedb…
Density Flow in Dynamical Networks via Mean-Field Games
2016
Current distributed routing control algorithms for dynamic networks model networks using the time evolution of density at network edges, while the routing control algorithm ensures edge density to converge to a Wardrop equilibrium, which was characterized by an equal traffic density on all used paths. We rearrange the density model to recast the problem within the framework of mean-field games. In doing that, we illustrate an extended state-space solution approach and we study the stochastic case where the density evolution is driven by a Brownian motion. Further, we investigate the case where the density evolution is perturbed by a bounded adversarial disturbance. For both the stochastic a…