Search results for "Automobile"
showing 10 items of 257 documents
Energy Efficiency Optimization for Multi-cell Massive MIMO : Centralized and Distributed Power Allocation Algorithms
2021
This paper investigates the energy efficiency (EE) optimization in downlink multi-cell massive multiple-input multiple-output (MIMO). In our research, the statistical channel state information (CSI) is exploited to reduce the signaling overhead. To maximize the minimum EE among the neighbouring cells, we design the transmit covariance matrices for each base station (BS). Specifically, optimization schemes for this max-min EE problem are developed, in the centralized and distributed ways, respectively. To obtain the transmit covariance matrices, we first find out the closed-form optimal transmit eigenmatrices for the BS in each cell, and convert the original transmit covariance matrices desi…
Collaborative Mobile Clouds: An Energy Efficient Paradigm for Content Sharing
2018
On the way toward enabling efficient content distribution, reducing energy consumption and prolonging battery life of mobile equipment, an emerging paradigm, i.e., mobile cloud, which is based on content distribution, was proposed. As a mobile platform that is oriented toward content distribution, mobile cloud is also foreseen as an energy-efficient solution for future wireless networks. The benefits of using CMC for content distribution or distributed computing from social networking perspectives have been studied earlier. In this article, we first present the concepts of CMC and then discuss the energy-efficiency benefits from the system-level point-of-view as well as open challenges in d…
Medico-legal implications of sleep apnoea syndrome: driving license regulations in Europe.
2008
Background: Sleep apnoea syndrome (SAS), one of the main medical causes of excessive daytime sleepiness, has been shown to be a risk factor for traffic accidents. Treating SAS results in a normalized rate of traffic accidents. As part of the COST Action B-26, we looked at driving license regulations, and especially at its medical aspects in the European region. Methods: We obtained data from Transport Authorities in 25 countries (Austria, AT; Belgium, BE; Czech Republic, CZ; Denmark, DK; Estonia, EE; Finland, FI; France, FR; Germany, DE; Greece, GR; Hungary, HU; Ireland, IE; Italy, IT; Lithuania, LT; Luxembourg, LU; Malta, MT; Netherlands, NL; Norway, EC; Poland, PL; Portugal, PT; Slovakia,…
Equipement automobile et domicile-travail dans l'espace français métropolitain vus par le Recensement
2020
Colloque : Peut-on se passer de la voiture hors des centres urbains ?, Guyancourt, FRANCE, 27-/02/2020 - 27/02/2020; Selon les recensements récents de la population (RP), la très grande majorité des actifs déclarent aller travailler en voiture. Cette source permet de discuter, pour la période 2006-2016, l'affirmation selon laquelle la voiture serait toujours plus indispensable hors des grands centres urbains où, au contraire, son utilisation et sa possession stagneraient. Le recensement a ses limites, mais il permet de cartographier finement les pratiques dans tout le pays et de les analyser selon des typologies géographiques adaptées aux problématiques du transport. Il permet aussi de…
Driver training interests of a Spanish sample of young drivers and its relationship with their self-assessment skills concerning risky driving behavi…
2013
Abstract Poor driving self-assessment skills (e.g., over-confidence) have been pointed out as an important explanatory factor behind young drivers’ accident involvement. This paper explores (1) what young drivers miss in their training as drivers in order to analyze whether an assessment of one's own driving skills plays an important role in their desire to improve as drivers, and (2) how these training interests are related to an estimate of their self-assessment skills concerning risky driving behavior. For this purpose, a study was conducted using a survey with a blocked sampling design of novice drivers. The survey solicited respondents’ self-report about (1) the contents of training co…
Acceptance of truck platooning by professional drivers on German highways. A mixed methods approach.
2020
Abstract Truck platoon driving is a current branch of automated driving, which has the potential to radically change the work routine of professional drivers. In a platoon system, one truck (semi-)automatically follows a lead truck with a reduced distance, which produces significant savings in fuel and enables better traffic flow. In a current application of truck platoon driving, the following vehicle operates at level-2 automation. Thus, the driver of the following truck merely has to supervise the semi-automated system, which takes over steering and speed control when engaged. Level-2 truck platoon driving had not been tested with professional drivers in real traffic before. We hypothesi…
Decoupled Downlink-Uplink Coverage Analysis with Interference Management for Enriched Heterogeneous Cellular Networks
2016
Heterogeneous cellular networks (HetCNets) offer a promising solution to cope with the current cellular coverage crunch. Due to the large transmit power disparity, while following maximum power received (MPR) association scheme, a larger number of users are associated with macro-cell BS (MBS) than small-cell BSs (SBSs). Therefore, an imbalance load arrangement takes place across the HetCNets. Hence, using cell range expansion-based cell association, we can balance the load across the congested MBS. However, using MPR association scheme, users’ offloading leads to two challenges: 1) macro-cell interference , in which the MBS interferes with the offloaded users, and 2) coupled downlink-uplink…
More aware, more protected: a cross-sectional study on road safety skills predicting the use of passive safety elements among Spanish teenagers
2019
ObjectiveThis study had two objectives: first, to test the effects of sociodemographic variables, and the effects of three key road safety skills (knowledge–risk perception–attitudes) on the use of passive safety elements (PSEs) among teenagers; and second, to assess the differential impact of the study variables on PSEs use from a gender-based perspective.Setting and participantsThis cross-sectional study was framed in the paradigm of primary care, and it involved students from several educational centres in Spain. A sample of 827 Spanish teenagers (52.4% females and 47.6% males) with a mean age of M=14.41–7 (12–19) years was used.ResultsThrough SEM modelling, we found that the use of PSEs…
An energy and power based approach toward design of power split for urban hybrid vehicle
2011
This work presents a novel method of analyzing real and artificial urban driving cycles with regard to power and energy needs. The results can be used to facilitate the design of the power split between primary and secondary power sources for hybrid vehicles in urban applications. Based on the analysis of different real and artificial driving cycles three key values are defined that allow predefining the size of the primary and secondary power source.
Energy Efficiency Evaluation of Cellular Networks Based on Spatial Distributions of Traffic Load and Power Consumption
2013
Energy efficiency has gained its significance when service providers' operational costs burden with the rapidly growing data traffic demand in cellular networks. In this paper, we propose an energy efficiency model for Poisson-Voronoi tessellation (PVT) cellular networks considering spatial distributions of traffic load and power consumption. The spatial distributions of traffic load and power consumption are derived for a typical PVT cell, and can be directly extended to the whole PVT cellular network based on the Palm theory. Furthermore, the energy efficiency of PVT cellular networks is evaluated by taking into account traffic load characteristics, wireless channel effects and interferen…