Search results for " traffic"
showing 10 items of 384 documents
The role of the Access Point in Wi-Fi networks with selfish nodes
2009
In Wi-Fi networks, mobile nodes compete for accessing the shared channel by means of a random access protocol called Distributed Coordination Function (DCF), which is long term fair. But recent drivers allow users to configure protocol parameters differently from their standard values in order to break the protocol fairness and obtain a larger share of the available bandwidth at the expense of other users. This motivates a game theoretical analysis of DCF. Previous studies have already modeled access to a shared wireless channel in terms of non-cooperative games among the nodes, but they have mainly considered ad hoc mode operation. In this paper we consider the role of the Access Point (AP…
PV-Alert: A fog-based architecture for safeguarding vulnerable road users
2017
International audience; High volumes of pedestrians, cyclists and other vulnerable road users (VRUs) have much higher casualty rates per mile; not surprising given their lack of protection from an accident. In order to alleviate the problem, sensing capabilities of smartphones can be used to detect, warn and safeguard these road users. In this research we propose an infrastructure-less fog-based architecture named PV-Alert (Pedestrian-Vehicle Alert) where fog nodes process delay sensitive data obtained from smartphones for alerting pedestrians and drivers before sending the data to the cloud for further analysis. Fog computing is considered in developing the architecture since it is an emer…
Resource sharing optimality in WiFi infrastructure networks
2009
In WiFi networks, mobile nodes compete for accessing a shared channel by means of a random access protocol called Distributed Coordination Function (DCF). Although this protocol is in principle fair, since all the stations have the same probability to transmit on the channel, it has been shown that unfair behaviors may emerge in actual networking scenarios. Assuming that a contending node can dynamically change its strategy, by tuning its contention parameters to non-standard values on the basis of channel observations, we prove that, for infrastructure networks with bidirectional traffic and homogeneous application requirements, selfish access strategies are able to reach equilibrium condi…
Performance analysis of selfish access strategies on WiFi infrastructure networks
2009
In this paper we propose a game-theoretic approach for characterizing WiFi network performance in presence of intelligent nodes employing cognitive functionalities. We assume that a cognitive WiFi node is aware of its application requirements and is able to dynamically estimate the network status, in order to dynamically change its access strategy by tuning the contention window settings. We prove that, for infrastructure networks with bidirectional traffic and homogeneous application requirements, selfish access strategies are able to reach equilibrium conditions, which are also Pareto optimal. Indeed, we show that the station strategies converge toward values which maximize a per-node uti…
The Ups and Downs of Camera-Monitor Systems: The Effect of Camera Position on Rearward Distance Perception
2020
Objective This study investigates the effects of different positions of side-mounted rear-view cameras on distance estimation of drivers. Background Camera-monitor systems bring advantages as compared to conventional rear-view mirrors, such as improved aerodynamics and enlarged field-of-view. Applied research has mainly focused on the comparison between cameras and mirrors or on positioning of in-vehicle monitors. However, the positioning of the exterior camera awaits investigation given that the perspective of the observer at does affect depth perception at large. Method In two experiments, a total of 50 students estimated metric distances to static vehicles presented in realistic or 3D-re…
UbiRoad: Semantic Middleware for Context-Aware Smart Road Environments
2010
A smart road environment is such a traffic environment that is equipped with all necessary facilities to enable seamless mobile service provisioning to the users. However, advanced sensors and network architectures deployed within the traffic environment are insufficient to make mobile service provisioning autonomous and proactive, thus minimizing drivers’ distraction during their presence in the environment. For that, an Intelligent Transportation System, which is operating on top of numerous sensor and access networks and governing the process of mobile services provisioning to the users in self-managed and proactive way, must be deployed. Specifically, such system should provide solution…
On the Applicability of the Space Syntax Methodology for the Determination of Street Lighting Classes
2020
Street lighting plays a crucial role in a city’s night landscape and in urban traffic management, influencing users’ comfort and safety. To contain costs of public street lighting systems and to avoid energy waste, illuminance levels on road surfaces must be adequate to fit actual traffic volumes, as prescribed by regulations. This is true not only for motorized roads but also for sidewalks, paths, and pedestrian areas. Regulations in force establish a relationship between road traffic volumes and minimum illuminance levels through the lighting classes selection procedure. Lighting classes selection is based on various para meters among which traffic volume is the most difficult to evaluate…
Affari e complicità mafiose tra Palermo e Punta Raisi
2014
La storia dello scalo aeroportuale di Punta Raisi – oggi intitolato alla memoria di Giovanni Falcone e Paolo Borsellino – prende avvio nel secondo dopoguerra, in coincidenza con l’incremento del traffico aereo civile nei cieli del capoluogo siciliano, terzo in Italia per numero di transiti di passeggeri e merci, con cifre non più sostenibili dall’aeroporto militare di Boccadifalco. Tutto inizia con la costituzione, nel 1953, del Consorzio Autonomo per l'Aeroporto di Palermo, con l’obiettivo di realizzare il progetto di una nuova infrastruttura civile a pochi passi dal centro urbano, pronta a sostenere la concorrenza con i migliori scali del Paese e a rilanciare la modernizzazione dei commer…
Determinants of vaccine hesitancy and effectiveness of vaccination counseling interventions among a sample of the general population in Palermo, Ital…
2020
Counteract vaccine hesitancy is a public health priority. Main objectives of the cross-sectional study conducted were to evaluate knowledge, attitudes, and behaviors regarding vaccination issues, to estimate the prevalence of vaccine hesitancy and to estimate the effectiveness of vaccination counseling on community advocacy in a sample of general population. An anonymous validated questionnaire was administered in April 2017 at the main shopping center of Palermo and was followed by tailored vaccination counseling interventions. To estimate the effectiveness of the interventions four main connection parameters to the vaccinarsi.org website were evaluated, in the two months before and after …
Il traffico di migranti nel Mediterraneo: validità della legge penale e tutela della persona
2019
Studio giuridico comparato in materia di repressione al traffico di migranti nell'ambito dell'Unione Europea con specifico riguardo al reato di favoreggiamento dell'immigrazione clandestina in Italia, Spagna e Germania e i relativi problemi di giurisdizione penale che solleva questo specifico fenomeno all'interno del bacino mediterraneo. Comparative analysis on the repression of smuggling of migrants within the EU legal framework with specific regard to domestic legislations in Italy, Spain and Germany and the jurisdictional issues which arise in such specific phenomenon. This work is part of the final deliverable of a Research Project funded by Philip Morris International (PMI-Impact) ("Th…